CVPN-956: renaming metric for consistency

[kp-stanislav-baiduzhyi]

Using naming that is consistent with other metrics being produced

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• The correct base branch is being used, if not main

[github-actions]

Code coverage summary for 8b1180c:

Filename                                                     Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
lightway-app-utils/src/args/cipher.rs                              7                 7     0.00%           2                 2     0.00%           6                 6     0.00%           0                 0         -
lightway-app-utils/src/args/connection_type.rs                     7                 7     0.00%           2                 2     0.00%           6                 6     0.00%           0                 0         -
lightway-app-utils/src/args/duration.rs                           10                10     0.00%           6                 6     0.00%          14                14     0.00%           0                 0         -
lightway-app-utils/src/args/logging.rs                            20                20     0.00%           4                 4     0.00%          18                18     0.00%           0                 0         -
lightway-app-utils/src/connection_ticker.rs                       35                 4    88.57%          17                 2    88.24%         182                 5    97.25%           0                 0         -
lightway-app-utils/src/dplpmtud_timer.rs                          53                 7    86.79%          22                 4    81.82%         323                11    96.59%           0                 0         -
lightway-app-utils/src/event_stream.rs                             6                 0   100.00%           3                 0   100.00%          13                 0   100.00%           0                 0         -
lightway-app-utils/src/iouring.rs                                102               102     0.00%          20                20     0.00%         190               190     0.00%           0                 0         -
lightway-app-utils/src/metrics.rs                                  2                 2     0.00%           1                 1     0.00%           3                 3     0.00%           0                 0         -
lightway-app-utils/src/tun.rs                                     89                89     0.00%          23                23     0.00%          96                96     0.00%           0                 0         -
lightway-app-utils/src/utils.rs                                    8                 8     0.00%           1                 1     0.00%           9                 9     0.00%           0                 0         -
lightway-client/src/args.rs                                       32                32     0.00%          30                30     0.00%          30                30     0.00%           0                 0         -
lightway-client/src/io/inside/tun.rs                              42                42     0.00%           7                 7     0.00%          50                50     0.00%           0                 0         -
lightway-client/src/io/outside/tcp.rs                             47                47     0.00%           9                 9     0.00%          43                43     0.00%           0                 0         -
lightway-client/src/io/outside/udp.rs                             58                58     0.00%          11                11     0.00%          58                58     0.00%           0                 0         -
lightway-client/src/io/outside/udp/sockopt.rs                     23                23     0.00%           4                 4     0.00%          66                66     0.00%           0                 0         -
lightway-client/src/keepalive.rs                                 185                35    81.08%          46                 7    84.78%         397                21    94.71%           0                 0         -
lightway-client/src/lib.rs                                       132               132     0.00%          15                15     0.00%         188               188     0.00%           0                 0         -
lightway-client/src/main.rs                                       20                20     0.00%           2                 2     0.00%         122               122     0.00%           0                 0         -
lightway-core/src/borrowed_bytesmut.rs                            87                 1    98.85%          24                 0   100.00%         196                 1    99.49%           0                 0         -
lightway-core/src/builder_predicates.rs                           20                10    50.00%           4                 2    50.00%          32                16    50.00%           0                 0         -
lightway-core/src/cipher.rs                                       10                 0   100.00%           4                 0   100.00%          14                 0   100.00%           0                 0         -
lightway-core/src/connection.rs                                  469               231    50.75%          50                19    62.00%         652               272    58.28%           0                 0         -
lightway-core/src/connection/builders.rs                          64                24    62.50%          18                 7    61.11%         219                49    77.63%           0                 0         -
lightway-core/src/connection/dplpmtud.rs                         767                90    88.27%          69                 1    98.55%         950                11    98.84%           0                 0         -
lightway-core/src/connection/fragment_map.rs                     141                13    90.78%          30                 1    96.67%         293                 8    97.27%           0                 0         -
lightway-core/src/connection/io_adapter.rs                       146                17    88.36%          42                 5    88.10%         338                23    93.20%           0                 0         -
lightway-core/src/context.rs                                      97                29    70.10%          28                 9    67.86%         201                42    79.10%           0                 0         -
lightway-core/src/context/ip_pool.rs                               7                 3    57.14%           1                 0   100.00%           6                 0   100.00%           0                 0         -
lightway-core/src/context/server_auth.rs                          14                11    21.43%           4                 3    25.00%          19                15    21.05%           0                 0         -
lightway-core/src/io.rs                                            3                 3     0.00%           3                 3     0.00%          10                10     0.00%           0                 0         -
lightway-core/src/lib.rs                                           9                 6    33.33%           4                 1    75.00%          18                 9    50.00%           0                 0         -
lightway-core/src/metrics.rs                                       7                 7     0.00%           3                 3     0.00%          10                10     0.00%           0                 0         -
lightway-core/src/packet.rs                                       29                 9    68.97%           5                 2    60.00%          31                 7    77.42%           0                 0         -
lightway-core/src/plugin.rs                                       73                11    84.93%          27                 7    74.07%         164                11    93.29%           0                 0         -
lightway-core/src/utils.rs                                       111                19    82.88%          26                 0   100.00%         184                11    94.02%           0                 0         -
lightway-core/src/version.rs                                      49                 0   100.00%          24                 0   100.00%          94                 0   100.00%           0                 0         -
lightway-core/src/wire.rs                                        152                22    85.53%          39                 1    97.44%         262                 3    98.85%           0                 0         -
lightway-core/src/wire/auth_failure.rs                             9                 1    88.89%           3                 0   100.00%          19                 0   100.00%           0                 0         -
lightway-core/src/wire/auth_request.rs                           152                12    92.11%          36                 0   100.00%         289                 0   100.00%           0                 0         -
lightway-core/src/wire/auth_success_with_config_ipv4.rs           69                 4    94.20%          13                 0   100.00%         145                 0   100.00%           0                 0         -
lightway-core/src/wire/data.rs                                    21                 1    95.24%           7                 0   100.00%          41                 0   100.00%           0                 0         -
lightway-core/src/wire/data_frag.rs                               47                 1    97.87%          19                 0   100.00%          94                 0   100.00%           0                 0         -
lightway-core/src/wire/ping.rs                                    24                 3    87.50%           8                 0   100.00%          69                 0   100.00%           0                 0         -
lightway-core/src/wire/pong.rs                                    15                 2    86.67%           5                 0   100.00%          34                 0   100.00%           0                 0         -
lightway-core/src/wire/server_config.rs                           20                 2    90.00%           5                 0   100.00%          44                 0   100.00%           0                 0         -
lightway-server/src/args.rs                                       29                29     0.00%          27                27     0.00%          27                27     0.00%           0                 0         -
lightway-server/src/connection.rs                                 48                48     0.00%          23                23     0.00%         105               105     0.00%           0                 0         -
lightway-server/src/connection_manager.rs                         99                99     0.00%          31                31     0.00%         187               187     0.00%           0                 0         -
lightway-server/src/connection_manager/connection_map.rs          92                10    89.13%          28                 3    89.29%         275                 9    96.73%           0                 0         -
lightway-server/src/io/inside/tun.rs                              27                27     0.00%           7                 7     0.00%          34                34     0.00%           0                 0         -
lightway-server/src/io/outside/tcp.rs                             33                33     0.00%           6                 6     0.00%          40                40     0.00%           0                 0         -
lightway-server/src/io/outside/udp.rs                             41                41     0.00%          10                10     0.00%          59                59     0.00%           0                 0         -
lightway-server/src/ip_manager.rs                                134                24    82.09%          29                 4    86.21%         325                26    92.00%           0                 0         -
lightway-server/src/lib.rs                                        77                77     0.00%          10                10     0.00%         121               121     0.00%           0                 0         -
lightway-server/src/main.rs                                       39                39     0.00%           5                 5     0.00%         128               128     0.00%           0                 0         -
lightway-server/src/metrics.rs                                    70                68     2.86%          29                28     3.45%         113               110     2.65%           0                 0         -
lightway-server/src/statistics.rs                                 56                24    57.14%           9                 4    55.56%         104                42    59.62%           0                 0         -
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                           4235              1696    59.95%         940               372    60.43%        7760              2322    70.08%           0                 0         -

✅ Region coverage 59% passes
✅ Line coverage 70% passes