[Enhancement] Setup auth token utils for obo

[RyanL1997]

Description

Setup auth token utils for obo

• Category (Enhancement, New feature, Bug fix, Test fix, Refactoring, Maintenance, Documentation)
  Enhancement, New feature

Issues Resolved

• Resolve [Enhancement] Set up a Util class for OBO Authenticator for key checks and endpoints checks #3238

Check List

• New functionality includes testing
• New functionality has been documented
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov]

Codecov Report

Merging #3419 (78ce0e7) into main (8628a89) will increase coverage by 0.28%.
Report is 6 commits behind head on main.
The diff coverage is 61.53%.

@@             Coverage Diff              @@
##               main    #3419      +/-   ##
============================================
+ Coverage     64.23%   64.52%   +0.28%     
- Complexity     3490     3546      +56     
============================================
  Files           264      269       +5     
  Lines         20152    20363     +211     
  Branches       3363     3375      +12     
============================================
+ Hits          12945    13139     +194     
+ Misses         5530     5529       -1     
- Partials       1677     1695      +18     

Files	Coverage Δ
...g/opensearch/security/authtoken/jwt/JwtVendor.java	75.75% <100.00%> (ø)
...nsearch/security/http/OnBehalfOfAuthenticator.java	68.31% <0.00%> (+0.66%)	⬆️
...ch/security/securityconf/DynamicConfigModelV7.java	66.30% <0.00%> (ø)
...a/org/opensearch/security/util/AuthTokenUtils.java	62.50% <62.50%> (ø)

... and 19 files with indirect coverage changes

[DarshitChanpura]

Left some suggestions to clean up code.

[RyanL1997]

Hi @DarshitChanpura, thanks for the feedbacks. I have applied those changes.

[DarshitChanpura]

LGTM!

[stephen-crawford]

Should probably add unit tests but because of the timeline for the 2.11 release, we can make do with a fast follow-up in my opinion.

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/security/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/security/backport-2.x
# Create a new branch
git switch --create backport/backport-3419-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 1ffa23cc96a6bf96752c33b7f134e4e6139dc828
# Push it to GitHub
git push --set-upstream origin backport/backport-3419-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/security/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-3419-to-2.x.

[RyanL1997]

Btw the unit tests has been added for this PR.