Refactor gdata

What does this MR do?

This MR is a part of refactoring from https://gitlab.com/foodsharing-dev/issues0/issues/353 and by that implement https://gitlab.com/foodsharing-dev/issues0/issues/378 as well.

It

• removes the usage of g_data for setting form data from Foodbasket and fairteiler module
  • prepares v_form_select, v_form_text, v_form_radio, v_form_textarea, v_form_tagselect to get all options supplied as parameters
• removes usage of g_data from all location pickers
• changes the handling of default location on all location pickers (e.g. profile edit, store edit...)
• Implements a $request and $response object - both are only partially used e.g. in WorkGroupControl
  • keeps support for "legacy" request/response handling until it can be removed
• Add single v_ components as twig partials to have WorkGroupControl::list as a full-page twig template rendering from within the controller
• Implements a proposal for an input sanitizer/validator that is used in WorkGroupControl
• Fixes some discovered bugs regarding permissions when editing FairTeiler
• Add tests for FairTeiler create/edit and Group list/edit
• Remove separated handling of address/house number for Stores to behave like all other instances of latLonPicker

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

Puh... Tests seem good and I have a pretty good coverage. Needs spot-testing in beta anyway (Store edit, Group list)

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 (but noone wanted so far :D)
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))