Move list stores for region to RestAPI

Closes #1449 (closed) - Task List of stores in region

What does this MR do?

Moves business logic to StoreTransactions and clean up source code around list stores of regions. Cleans up StoreControl for list stores so that the same code can be used by RestAPI.

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

Should Not influence

Links to related issues

How to test

Screenshots (if applicable)

Checklist

• add tests for all new stuff
• 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