Automate provisioning of Certificate resources for VirtualServer resources using cert-manager

[ciarams87]

Proposed changes

This PR implements a cert-manager controller to automate the provision and management of Certificate resources for VirtualServer resources using cert-manager. This mimics the functionality available for Ingress and Gateway resources (see https://cert-manager.io/docs/usage/gateway/).

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[codecov-commenter]

Codecov Report

Merging #2572 (0e30eeb) into main (ae4cb94) will increase coverage by 0.06%.
The diff coverage is 56.54%.

❗ Current head 0e30eeb differs from pull request most recent head 9fa11ed. Consider uploading reports for the commit 9fa11ed to get more accurate results

@@            Coverage Diff             @@
##             main    #2572      +/-   ##
==========================================
+ Coverage   53.50%   53.56%   +0.06%     
==========================================
  Files          49       52       +3     
  Lines       14299    14675     +376     
==========================================
+ Hits         7651     7861     +210     
- Misses       6407     6554     +147     
- Partials      241      260      +19     

Impacted Files	Coverage Δ
cmd/nginx-ingress/main.go	6.91% <0.00%> (-0.07%)	⬇️
internal/configs/config_params.go	76.74% <ø> (ø)
internal/k8s/controller.go	10.87% <0.00%> (-0.04%)	⬇️
internal/certmanager/cm_controller.go	18.80% <18.80%> (ø)
internal/certmanager/sync.go	71.65% <71.65%> (ø)
pkg/apis/configuration/validation/virtualserver.go	96.21% <82.60%> (-0.04%)	⬇️
internal/certmanager/helper.go	100.00% <100.00%> (ø)
internal/k8s/configuration.go	95.47% <0.00%> (-0.39%)	⬇️

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