Draft: Disable email notifications for new topics in region forums

Closes #179 (closed)

What does this MR do?

the user has now a new section in user settings -> notifications with an entry per region to get or not get mail notification for new forum threads

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

still working on it, but mostly frontend changes

Links to related issues

#179 (closed)

How to test

1. Checkout branch locally
2. Login as foodsaver 1
3. open user settings -> notifications
4. enable or disable notification for a specific district
5. login as other foodsaver 2 and create a new thread with mail notification to all users in district
6. check mail-dev server for mails to foodsaver 1
7. find mail for setting enabled, or no mail for setting disabled

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

Der Benutzer hat jetzt einen neuen Abschnitt in den Benutzereinstellungen -> Benachrichtigungen mit einem Eintrag pro Region, um E-Mail-Benachrichtigungen für neue Forenthreads zu erhalten oder nicht zu erhalten