feat: Use managed-by annotation

[dthomson25]

Closes #443 by introducing a new annotation called argo-rollouts.argoproj.io/managed-by-rollouts that indicates a Service is managed by a Rollout.

[codecov]

Codecov Report

Merging #448 into master will decrease coverage by 0.19%.
The diff coverage is 86.66%.

@@            Coverage Diff             @@
##           master     #448      +/-   ##
==========================================
- Coverage   85.20%   85.01%   -0.20%     
==========================================
  Files          80       80              
  Lines        7478     7415      -63     
==========================================
- Hits         6372     6304      -68     
- Misses        798      799       +1     
- Partials      308      312       +4     

Impacted Files	Coverage Δ
utils/conditions/conditions.go	88.95% <ø> (ø)
service/service.go	62.96% <84.61%> (+4.39%)	⬆️
rollout/service.go	87.38% <87.50%> (-0.25%)	⬇️
utils/service/service.go	100.00% <100.00%> (ø)
pkg/kubectl-argo-rollouts/info/replicaset_info.go	78.94% <0.00%> (-5.50%)	⬇️
experiments/experiment.go	93.14% <0.00%> (-0.51%)	⬇️

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