Creating OIDC Issuer resource

[IaroslavTitov]

Summary

• Fixes: Create a new resource oidc issuer #349
• Adding new OIDC Issuer resource
• Adding OIDC client
• Adding standard diff logic, to reuse in most (if not all!) resources - this would be used in Standardize Diff methods #481
• @glena , please take a look, since I only know the basics when it comes to how OIDC works, let me know if this makes sense

Testing

• Adding examples/integ tests in C#, TS, yaml
• I had to add service-provider-test-org2 and service-provider-test-org3, since otherwise examples would collide with each other

[github-actions]

Does the PR have any schema changes?

Looking good! No breaking changes found.

New resources:

• index.OidcIssuer

Maintainer note: consult the runbook for dealing with any breaking changes.

[glena]

I think it looks ok but didnt dive into details, LGTM

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 0.00%. Comparing base (183d805) to head (acb31fc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@     Coverage Diff     @@
##   main   #484   +/-   ##
===========================
===========================

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.