Minor updates for the voting tool frontend

Part of #975

What does this MR do?

• When creating a poll, the confirmation modal now disappears after clicking "send" so that you don't accidentally submit the form twice.
• The results of a score voting show the average instead of the sum
• The region name in a poll is now a link to that region

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

very sure, only frontend changes

How to test

1. Checkout branch locally
2. Login as uservoting1

Confirmation modal:

1. In the polls list in region Göttingen, create a new poll
2. Fill in some values, submit it
3. After confirming, the modal should disappear

Results of score voting:

1. Go to the polls list in region Göttingen
2. Find one that is a score voting
3. The column on the right should show the average value

Region link:

1. Should be visible on any poll's page

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

Kleine Anpassungen im Abstimmungsmodul: der Bezirksname in der Abstimmung verlinkt jetzt auf den Bezirk, in den Ergebnissen einer Bewertungswahl wird der Mittelwert statt der Summe angezeigt und das Formular zum Erstellen einer Abstimmung kann nicht mehr versehentlich doppelt abgesendet werden.