Draft: Introduce a region DTO

Part of #939

What does this MR do?

I would like to add more DTOs to the backend code to make the code more readable. Also, in many places it is not obvious which data is already there, which leads to unnecessary requests on the database. For example, RegionGateway::getRegionDetails makes a lot of requests but is sometimes used if only one specific value is needed.

This adds a first DTO and replaces the usage in some places.

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

Quite sure, I only replaced the most obvious cases

Links to related issues

How to test

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.