Extend Organizations administration API

[Awaleed]

Adds the Keycloak 26 Organizations endpoints needed to manage members and invitations.

• list/get/remove organization members
• list/get/resend/delete organization invitations
• return an organization ID from the create response
• allow callers to configure the Keycloak version and skip the server-info request
• serialize backed enums in criteria

Verification:

• vendor/bin/phpunit --testsuite unit --no-coverage (181 tests, 417 assertions)
• composer phpstan
• composer cs

[codecov]

Codecov Report

❌ Patch coverage is 62.31884% with 26 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.19%. Comparing base (015df9b) to head (b8cc1eb).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/Resource/Organizations.php	65.57%	21 Missing ⚠️
src/Builder.php	0.00%	3 Missing ⚠️
src/Http/Criteria.php	33.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #183      +/-   ##
==========================================
- Coverage   92.18%   90.19%   -1.99%     
==========================================
  Files          32       32              
  Lines         972     1040      +68     
==========================================
+ Hits          896      938      +42     
- Misses         76      102      +26     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[fschmtt]

Hi @Awaleed is this PR still a draft or ready for review?