* adds modal_generic.html template for generic usage
* adds M2M field log to BaseObject
* adds show log button to controls.html
* adds logging on adding related objects
* adds render log table using generic modal
* adds tooltip to missing values in detail views
* adds/updates translations
* moves diff_states message back to table top for direct presentation in compensation/detail/view.html
* removes diff_states rendering in deadline card in compensation/detail/view.html
* fixes before_state adding based on GET parameter
* refactors UserActionlogEntryEnum into a UserAction TextChoice (Django 3.x)
* adds ordering of compensation states depending on surface value
* refactors ServerMessageImportance from enum into TextChoice (Django 3.x)
* adds/updates translations
* adds UserActionLogEntry model to user/models.py
* wraps user and timestamp info
* can be extended for more information in the future
* refactors all filtering and accessing on values
