JWT Headers security module

[davidblasby]

WIP - in progress. Added PR for early review. Test coverage is about 90%.

This is a new Security Module - that follows the GeoServer JWT Header security module so they can be used in exactly the same manner.

See the added docs for more details.

This relies on a shared module with GS - I expect this will take a little bit to become available.

org.geoserver.community.jwt-headers jwt-headers-util 2.25-SNAPSHOT

The GeoServer module is broken into two parts - a shared part (jwt-headers-util) and a Geoserver-specific module (jwt-headers-gs).

Checklist

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

[davidblasby]

I GS went to v26, I need to update the dependencies and makes sure the GS PR is merged.

[davidblasby]

I've made changes based on jose's review. This will not build until a GS PR is merged (https://github.com/geoserver/geoserver/pull/7512).