OIDC Improvements and bug fixes

[xiechangning20]

Added pre-login filter to enable autologin, and restrict guest users
Added configuration for a OAuth2AuthorizedClientManager, which enables refreshing access token
Fixed the check for setting the userNameAttribute in GeonetworkOidcUserService.java and the Client Registration UserNameAttribute configuration in GeonetworkClientRegistrationProvider.java to based on OIDCConfig
Update the postLogoutRedirect endpoint to exclude default port numbers

• [✔️ ] I have read the contribution guidelines
• Pull request provided for main branch, backports managed with label
• [✔️ ] Good housekeeping of code, cleaning up comments, tests, and documentation
• [✔️ ] Clean commit history broken into understandable chucks, avoiding big commits with hundreds of files, cautious of reformatting and whitespace changes
• Clean commit messages, longer verbose messages are encouraged
• API Changes are identified in commit messages
• Testing provided for features or enhancements using automatic tests
• User documentation provided for new features or enhancements in manual
• Build documentation provided for development instructions in README.md files
• Library management using pom.xml dependency management. Update build documentation with intended library use and library tutorials or documentation

[CLAassistant]

All committers have signed the CLA.

[davidblasby]

please add javadoc to explain what this is doing

[xiechangning20]

Java docs added

[josegar74]

Add file header

[xiechangning20]

Added

[josegar74]

Add file header

[xiechangning20]

Added

[geonetworkbuild]

The backport to 4.2.x failed:

The process '/usr/bin/git' failed with exit code 1

stderr

The previous cherry-pick is now empty, possibly due to conflict resolution.
If you wish to commit it anyway, use:

    git commit --allow-empty

Otherwise, please use 'git cherry-pick --skip'

stdout

On branch backport-8761-to-4.2.x
You are currently cherry-picking commit ef51c8b246.
  (all conflicts fixed: run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

nothing to commit, working tree clean

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-4.2.x 4.2.x
# Navigate to the new working tree
cd .worktrees/backport-4.2.x
# Create a new branch
git switch --create backport-8761-to-4.2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick ef51c8b24699beadab1b021b3bd4a24924a21889,189bce83a5dd38c29b513133fe4bdc0d2883c0dd,c00fb2c366b0550ae1b327f25caf38ef680b8099,1deff2b019c71db748c6a8d67c6f3dd2b91d47ca,050e6a0a11e80a4ad81dfcd46073dc49ecb3fda7,b2eae4d9d552c9f5c92db588e7a40432c09ec1ae,39001dbb142dc64d3fd212cce8f0c691aa3c2bdd
# Push it to GitHub
git push --set-upstream origin backport-8761-to-4.2.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-4.2.x

Then, create a pull request where the base branch is 4.2.x and the compare/head branch is backport-8761-to-4.2.x.