feat: ability to customize cert-rotator's controller name

[chewong]

Cherry-picking #396 to release-0.12.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release-0.12@1898f84). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
pkg/rotator/rotator.go	0.00%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##             release-0.12     #397   +/-   ##
===============================================
  Coverage                ?   56.79%           
===============================================
  Files                   ?        1           
  Lines                   ?      574           
  Branches                ?        0           
===============================================
  Hits                    ?      326           
  Misses                  ?      183           
  Partials                ?       65           

Flag	Coverage Δ
unittests	56.79% <0.00%> (?)

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