Support list the partition specified in console

[zhangguoqing]

Is your feature request related to a problem? Please describe.
It 's maybe a subtask of the PR #1086, that from the discussion.

Describe the solution you'd like

1. The specified partition ID as the parameter.
   (user@ip) [space]> SHOW PART 666;
2. The result is sorted by partition IDs, so it maybe use the LIMIT clause easily.
   (user@ip) [space]> SHOW PARTS | LIMIT 666, 1
3. Both of the above are implemented.

Which solution should we choose?

[dangleptr]

I think we could support "show part $ID" firstly. It is more useful.

[zhangguoqing]

I think we could support "show part $ID" firstly. It is more useful.

OK, it will be implemented after the Issue #1173 is fixed. The leader distribution of partition is get from meta server directly.

[amber-moe]

Definitely, I think SHOW PARTS can be used with LIMIT is reasonable, after all, I'm not expecting a part list as long as 1024.

[critical27]

I guess SHOW PART 666 is enough for now.

[zhangguoqing]

@jude-zhu This issue is support show part $ID rather than show parts command!