Add support for KEDA ScaledObjects as an auto scaler

[aryan9600]

This PR adds support for KEDA ScaledObjects to be used as an auto scaler for workloads. A new ScalerReconciler named ScaledObjectReconciler has been introduced which reconciles ScaledObjects. Users can specify a reference to their existing ScaledObject using .spec.autoscalerRef in the Canary definition.

Fixes: #1118

[codecov-commenter]

Codecov Report

Merging #1216 (f68f291) into main (498f065) will increase coverage by 0.01%.
The diff coverage is 61.06%.

@@            Coverage Diff             @@
##             main    #1216      +/-   ##
==========================================
+ Coverage   54.72%   54.73%   +0.01%     
==========================================
  Files          80       81       +1     
  Lines        6822     6948     +126     
==========================================
+ Hits         3733     3803      +70     
- Misses       2510     2550      +40     
- Partials      579      595      +16     

Impacted Files	Coverage Δ
pkg/canary/factory.go	0.00% <0.00%> (ø)
pkg/controller/scheduler.go	45.87% <33.33%> (-0.73%)	⬇️
pkg/canary/scaled_object_reconciler.go	73.19% <73.19%> (ø)
pkg/controller/events.go	51.23% <0.00%> (-4.96%)	⬇️
pkg/router/contour.go	85.71% <0.00%> (-0.64%)	⬇️

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[stefanprodan]

This looks great, please add tests for primaryScalerQueries.

[stefanprodan]

LGTM

Thanks @aryan9600 🥇