feat(kcc): support kcc canary update

[gary-lgy]

What type of PR is this?

Features

What this PR does / why we need it:

Support canary update for KCC targets.

Which issue(s) this PR fixes:

Special notes for your reviewer:

[codecov]

Codecov Report

Attention: Patch coverage is 68.57749% with 148 lines in your changes missing coverage. Please review.

Project coverage is 55.98%. Comparing base (3269ac6) to head (3ad9448).

Files with missing lines	Patch %	Lines
pkg/controller/kcc/kcct.go	67.28%	110 Missing and 31 partials ⚠️
pkg/controller/kcc/util/kcct.go	85.18%	3 Missing and 1 partial ⚠️
pkg/controller/kcc/kcc.go	0.00%	1 Missing ⚠️
pkg/controller/kcc/target/target_handler.go	0.00%	1 Missing ⚠️
pkg/metaserver/kcc/manager.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #722      +/-   ##
==========================================
+ Coverage   55.80%   55.98%   +0.18%     
==========================================
  Files         594      593       -1     
  Lines       67830    67819      -11     
==========================================
+ Hits        37850    37968     +118     
+ Misses      25956    25846     -110     
+ Partials     4024     4005      -19     

Flag	Coverage Δ
unittest	55.98% <68.57%> (+0.18%)	⬆️

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