Support Command Palette

[janfaracik]

As part of https://github.com/jenkinsci/jenkins/pull/7569, Jenkins replaces the existing search input in the header for a Command Palette.

With this change the existing implementation of this plugin no longer works. https://github.com/jenkinsci/jenkins/pull/7569 however introduces support for plugins adding their own buttons to the navigation bar. This has briefly been discussed as a workaround so that this plugin can still continue to work.

This draft MR introduces a new button to the navigation bar, currently called 'Lucene' which allows users to navigate to the existing Lucene search page. On that page a new search input has been introduced, allowing users to search with Lucene as they previously could.

Testing done

See https://github.com/jenkinsci/lucene-search-plugin/pull/69#issuecomment-2242521900

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]

Searching for nothing via the new search bar and old search bar

Searching for 'built' via the new search bar and old search bar

Searching for 'feat' inside of a job via the new search bar and old search bar

The above scenarios work the same - there might be scenarios I'm unaware of so do let me know if I've missed anything.

[janfaracik]

Any thoughts on this @daniel-beck?