feat!: use v1beta1 in operator logic

[odubajDT]

This PR

• uses v1beta1 in operator logic
• cleanup of orphaned/deprecated functionality
• remove FeatureFlag controller
• remove duplications
• remove unneeded tests
• add more tests for uncovered use-cases
• minor workflow adaptation of e2e tests
• utilize common functions/constants to common package
• refactor common package
• remove unneeded config files from config folder
• cleanup webhook logic

Related Issues

Fixes #531

Depends on

open-feature/flagd#997

Notes

Currently the OFO is using custom build images of flagD, this will be chaned after open-feature/flagd#997 will be merged and released

[codecov]

Codecov Report

Merging #539 (f7c89e6) into main (e3c8b42) will increase coverage by 3.92%.
The diff coverage is 90.24%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #539      +/-   ##
==========================================
+ Coverage   77.94%   81.86%   +3.92%     
==========================================
  Files          10        7       -3     
  Lines        1020      805     -215     
==========================================
- Hits          795      659     -136     
+ Misses        189      118      -71     
+ Partials       36       28       -8     

Files	Coverage Δ
common/common.go	100.00% <100.00%> (ø)
common/flagdproxy/flagdproxy.go	82.18% <100.00%> (ø)
common/utils/utils.go	38.09% <100.00%> (ø)
webhooks/common.go	100.00% <100.00%> (ø)
webhooks/pod_webhook.go	82.35% <93.33%> (-7.29%)	⬇️
common/flagdinjector/flagdinjector.go	90.22% <82.75%> (ø)
controllers/core/featureflagsource/controller.go	46.37% <66.66%> (ø)

Flag	Coverage Δ
unit-tests	81.86% <90.24%> (+3.92%)	⬆️

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[Kavindu-Dodan]

Great progress. Needs to fix some conflicts and address few comments. Once done we can go for the release.

Proposal - we should make this a breaking change

[toddbaert]

Amazing.

Approving, pending conflict resolution and this.