Remove APIs which on longer make sense in heap based ObjectPool

[yufengwangca]

Problem

What is being fixed? Examples:

• The size of ObjectPool is not fixed under configuration flag CHIP_SYSTEM_CONFIG_POOL_USE_HEAP, therefore, some legacy index based APIs are no longer make sense. Currently, those APIs are only used by unit test.

Change overview

Remove APIs which do not make sense in heap based ObjectPool.

Testing

How was this tested? (at least one bullet point required)

• Checked with ./TestSystemObject since the removed APIs are only used in unit test.

[github-actions]

Size increase report for "esp32-example-build" from ed6fe72

File	Section	File	VM
chip-shell.elf	.flash.text	-56	-56
chip-bridge-app.elf	.flash.text	48	48
chip-temperature-measurement-app.elf	.flash.text	60	60
chip-lock-app.elf	.flash.text	-68	-68

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.riscv.attributes,0,-1
.debug_line,0,-3
.debug_loc,0,-40
.debug_abbrev,0,-268
.debug_str,0,-532
.debug_info,0,-1132

Comparing ./master_artifact/chip-pigweed-app.elf and ./pull_artifact/chip-pigweed-app.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize
[Unmapped],0,56
.debug_line,0,-10
.debug_loc,0,-13
.flash.text,-56,-56
.debug_abbrev,0,-318
.debug_str,0,-534
.debug_info,0,-1133

Comparing ./master_artifact/chip-bridge-app.elf and ./pull_artifact/chip-bridge-app.elf:

sections,vmsize,filesize
.flash.text,48,48
.debug_line,0,-10
[Unmapped],0,-48
.debug_loc,0,-61
.debug_abbrev,0,-318
.debug_str,0,-530
.debug_info,0,-1133

Comparing ./master_artifact/chip-persistent-storage.elf and ./pull_artifact/chip-persistent-storage.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-temperature-measurement-app.elf and ./pull_artifact/chip-temperature-measurement-app.elf:

sections,vmsize,filesize
.flash.text,60,60
.debug_line,0,-10
[Unmapped],0,-60
.debug_loc,0,-141
.debug_abbrev,0,-318
.debug_str,0,-534
.debug_info,0,-1133

Comparing ./master_artifact/chip-ipv6only-app.elf and ./pull_artifact/chip-ipv6only-app.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-lock-app.elf and ./pull_artifact/chip-lock-app.elf:

sections,vmsize,filesize
[Unmapped],0,68
.debug_loc,0,-8
.debug_line,0,-10
.flash.text,-68,-68
.debug_abbrev,0,-268
.debug_str,0,-530
.debug_info,0,-1132