Second follow-up from "Search improvements"

What does this MR do?

Speed and performance:

• Re-implement client side search for buddies and objects the user is member for
• Remove query words that are substrings of others
• Improve store search speed

Features:

• Allow opening the search with Shift+F
• Make result lists expandable and show only a few in collapsed state
• Display info if there are no results
• Display info on too short search terms
• Allow navigating results using tab effectively

Code style:

• Use php attributes for Rest API
• declare strict types on files newly added for the search
• Improved general code style

How confident are you it won't break things if deployed?

Confident, should be the next (and close to final) step towards an improved search.

Links to related issues

See #1728

Screenshots (if applicable)

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• set a "for:" label to indicate who will be affected by this change
• added to the next milestone (see https://gitlab.com/foodsharing-dev/foodsharing/-/milestones, unless it has a "for:Dev" label)
• added an entry to CHANGELOG.md
• added a short text in the release notes to /release-notes/YYYY-MM.md
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/region?bid=734&sub=forum. Please change the MRs label to "state:Beta testing".
  • Consider writing a detailed description in German.
  • Describe in a few sentences, what should be tested from a user perspective.
  • Also mention different settings (e.g. different browsers, roles, ...) how this change can be tested.
  • Be aware, that also non technical people should understand.