Refactor profile

What does this MR do?

As a preparation to profile changes, I have refactored the complete profile module which was quite hard to read. Hopefully, it got better.

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

Many changes so some beta testing will be needed for sure.

Links to related issues

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))