[1.12] Cherry Pick - add label selector in Resource Modifiers (#6704)

[anshulahuja98]

• add label selector in resource modifier

• add ut

• update after review

• update after review

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[codecov]

Codecov Report

Merging #6725 (4516550) into release-1.12 (5353013) will decrease coverage by 0.01%.
The diff coverage is 71.42%.

@@               Coverage Diff                @@
##           release-1.12    #6725      +/-   ##
================================================
- Coverage         60.36%   60.36%   -0.01%     
================================================
  Files               242      242              
  Lines             25979    25983       +4     
================================================
+ Hits              15683    15684       +1     
- Misses             9194     9196       +2     
- Partials           1102     1103       +1     

Files Changed	Coverage Δ
internal/resourcemodifiers/resource_modifiers.go	75.65% <66.66%> (-1.83%)	⬇️
.../resourcemodifiers/resource_modifiers_validator.go	100.00% <100.00%> (ø)