feat: add leader monitor

[ColdsteelRail]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

2. What is the scope of this PR (e.g. component or file name):

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

6. Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 38.33%. Comparing base (ccb9747) to head (fd3eba2).

Files with missing lines	Patch %	Lines
pkg/controllers/collaset/synccontrol/update.go	0.00%	1 Missing ⚠️
...g/controllers/operationjob/operationjob_manager.go	0.00%	1 Missing ⚠️
...rs/podtransitionrule/processor/rules/labelcheck.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #335       +/-   ##
===========================================
- Coverage   65.49%   38.33%   -27.16%     
===========================================
  Files          77      129       +52     
  Lines        5538     9479     +3941     
===========================================
+ Hits         3627     3634        +7     
- Misses       1571     5508     +3937     
+ Partials      340      337        -3     

Flag	Coverage Δ
unittests	38.33% <25.00%> (-27.16%)	⬇️

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