Rework selector labels

[KevinSnyderCodes]

Addresses #1312, #1257, #1115

Retains all matchLabels in the primary Deployment or DaemonSet, instead of picking the first one that matches the -selector-labels.

Still appends -primary to the value of the first label that matches -selector-labels. This ensures that the canary and primary have a unique set of selector labels.

Service selector also uses the full set of matchLabels and overrides the value of the first matching -selector-labels to route to canary or primary.

Does not recreate the primary Deployment or DaemonSet if the matchLabels of the existing object are not equal.

Does update the Service selector labels to match the new behavior.

[codecov-commenter]

Codecov Report

:x: Patch coverage is 64.17910% with 24 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 28.55%. Comparing base (12ee6cb) to head (24ffc5b). :warning: Report is 67 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/canary/daemonset_controller.go	68.00%	7 Missing and 1 partial :warning:
pkg/canary/deployment_controller.go	68.00%	7 Missing and 1 partial :warning:
pkg/canary/knative_controller.go	0.00%	2 Missing :warning:
pkg/canary/service_controller.go	0.00%	2 Missing :warning:
pkg/controller/finalizer.go	0.00%	2 Missing :warning:
pkg/router/factory.go	0.00%	2 Missing :warning:

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1830       +/-   ##
===========================================
- Coverage   39.44%   28.55%   -10.89%     
===========================================
  Files         287      287               
  Lines       22706    22827      +121     
===========================================
- Hits         8956     6518     -2438     
- Misses      12777    15579     +2802     
+ Partials      973      730      -243     

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