Revamp plugin

[janfaracik]

The intention is to overhaul the plugin, using a modern framework and design system, to ensure it's straightforward to maintain going forward. It takes heavy inspiration from the structure of http://github.com/jenkinsci/pipeline-graph-view-plugin/ - I've found that that works really quite well and makes development easy.

What's new?

• New user interface
  • Matches the new Jenkins header
  • Follows Jenkins Design Library
  • Now supports Customisable Header plugin
  • Now follows user theme
• Pages can now have descriptions (appears in the header)
• Reduce animations has been replaced with a media query (set reduced animations in your system settings instead)
• You can now jump between different build monitors via the breadcrumb
• New codebase in React
  • React 19, Vite, Rspack

Closes #61
Closes #348
Closes #743
Closes #744
Closes #747

TODO

• Improve error handling
• Improve badges
• Add JUnit support
• Add cause/blame support
• Update preview image in README

Testing done

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

[janfaracik]

This PR is now ready for testing - albeit not finished - would be great to get thoughts and feedback on this. Keen to get it released and iterate.