Feature/join region modal in vue

What does this MR do?

• Replaced BecomeBezirk with JoinRegionModal (Closes #874 (closed), Closes #1312 (closed))
• From #875 it filters workgroups, so they should not visible

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

9/10 - Requires !2293 (merged)

How to test

1. Checkout branch locally
2. Login as foodsharer
3. Complete Quiz
4. check if the modal is shown
5. also press the the checkbox

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 that can be used in the release notes
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/?page=bezirk&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.

Release notes text in German

Das Bezirk beitreten Modal ist jetzt etwas moderner.