feat: migrate flagd startup argument to sources flag

[Kavindu-Dodan]

Prerequisite

Release of flagd 0.4.6

This PR

Fixes #389

This PR migrate flagd side-car startup arguments from uri (flagd start --uri <sync-source>) to sources (flagd start --sources <sync-source>).

More on the new sources based configuration options [1]

With this option, I have introduced the grpc sync option to OFO and other grpc sync-provider options.

follow-up

Discussion - type SourceConfig can be referred from OFO dependency and avoid duplication at flagd

[1] - https://github.com/open-feature/flagd/blob/main/docs/configuration/configuration.md

[codecov]

Codecov Report

Merging #427 (06eb625) into main (651c63c) will increase coverage by 1.36%.
The diff coverage is 59.84%.

@@            Coverage Diff             @@
##             main     #427      +/-   ##
==========================================
+ Coverage   77.76%   79.13%   +1.36%     
==========================================
  Files          21       21              
  Lines        1300     1323      +23     
==========================================
+ Hits         1011     1047      +36     
+ Misses        248      234      -14     
- Partials       41       42       +1     

Impacted Files	Coverage Δ
...pis/core/v1alpha3/flagsourceconfiguration_types.go	100.00% <ø> (ø)
webhooks/pod_webhook.go	81.71% <55.65%> (+3.48%)	⬆️
...pis/core/v1alpha1/flagsourceconfiguration_types.go	98.78% <100.00%> (+0.01%)	⬆️
...ore/v1alpha3/flagsourceconfiguration_conversion.go	100.00% <100.00%> (ø)

Flag	Coverage Δ
component-tests	78.76% <55.65%> (+2.92%)	⬆️
unit-tests	61.37% <9.44%> (-0.32%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[james-milligan]

few small comments, but LGTM

[toddbaert]

Thanks for circling back to this after the related flagd changes. I tried to find something to be improved but I can't 😅 . LGTM.

[Kavindu-Dodan]

Thanks for circling back to this after the related flagd changes. I tried to find something to be improved but I can't 😅 . LGTM.

Thank you :)