Slightly refactor pickup-edit frontend

What does this MR do?

Refactor pickup-edit frontend ;-)

• introduce Milestone constants
• split out inline CSS, remove unused or duplicated rules
• remove most of the unused even/odd computations
• translate some strings, condense and move other translations
• build helper functions to replace (very!) repeated select options
• fix duplicate select options in newfetchtime rows
• refactor v_bezirkChooser to v_regionPicker
• FoodSharePoint translation and refactoring (this is a larger commit)
• annotate PageHelper

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

pretty sure

Links to related issues

• &22 (closed)
• &7 (closed)

How to test

• as store manager: view and edit the recurring pickup dates
• as store manager: add a new manual pickup date

Checklist

• no test: no functional changes
• no unrelated changes
• asked someone for a code review
• set a "for:" label to indicate who will be affected by this change
• use "state:" labels to track this MR's state until it was beta tested
• added an entry to CHANGELOG.md
• forDev => no release notes
• Once your MR has been merged, you are responsible to create a testing issue in Beta Testing Repo:
  • 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.