Add custom parameters to authorize and logout endpoints

[eva-mueller-coremedia]

This PR

• provides a different approach to solve Logout issue: Required String parameter 'redirect_uri' is not present #229 resp. New config option: Enable AWS Cognito Logout #241
• solves Allow query params for ID provider URLs #443

Additionally, some housekeeping (fixing typos, simplify statements) has been done.

The main change has been done in eb0d2ba:

• Add new input fields for login resp. logout query parameters in the Jenkins management backend
• maybeOpenIdLogoutEndpoint has been refactored when it comes to combining all parameters
• Login query parameters are not allowed to overwrite keys as defined in org.pac4j.oidc.config.OidcConfiguration
• Logout query parameters are not allowed to overwrite keys as set in maybeOpenIdLogoutEndpoint like id_token_hint, state, post_logout_redirect_uri

Testing done

This change has been tested by unit tests as well as local testing agains AWS Cognito.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[codecov]

Codecov Report

Attention: Patch coverage is 81.33333% with 14 lines in your changes missing coverage. Please review.

Project coverage is 72.78%. Comparing base (84359ac) to head (36fe900).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
...va/org/jenkinsci/plugins/oic/OicSecurityRealm.java	84.48%	6 Missing and 3 partials ⚠️
...i/plugins/oic/OicServerWellKnownConfiguration.java	50.00%	3 Missing ⚠️
...nsci/plugins/oic/OicServerManualConfiguration.java	81.81%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #480      +/-   ##
============================================
+ Coverage     71.73%   72.78%   +1.05%     
- Complexity      222      248      +26     
============================================
  Files            17       17              
  Lines          1033     1073      +40     
  Branches        148      152       +4     
============================================
+ Hits            741      781      +40     
- Misses          201      202       +1     
+ Partials         91       90       -1     

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