Make sure the custom add forms for event and room are correctly tested

Bump django-bootstrap to version 5
Exchange bootstrap files (js & css)
Adapt settings
Migrate to new version/resolve breaking changes
Move layout adaptions previously included in bootstrap.css into custom.css

Benjamin Hättasch authored 2 years ago and Nadja Geisler committed 2 years ago

Add flag (default value true)
Use for wiki export
Add migration, translation & test
This implements #178

This includes a new helper method to assert the existence of a particular message

Introduce framework to simply test correct rendering of views
Create tests for dashboard views
Create tests for plan views
Create tests for default admin views (add and change) of AKModel models