* 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 user/includes/contact_modal_button.html for calling contact data of a user
* adds user contact modal to intervention detail view
* adds 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
* adds modal form for adding payments
* generalizes generic_table_form.html for table-form-like usage in modal_form.html
* adds css enhancements for focused input fields
* adds BaseModalForm as specification to BaseForm, which inherits the BSModalForm class as well
* adds translations
* adds (WIP) detail view for interventions
* renames typo in conservations_file_number to conservation_file_number
* adds simple has_access check for intervention objects for given users
* renames occurences of "Registered" to "Recorded" (verzeichnen)
* adds an informing message for detail view of intervention objects which are not editable for a user
* adds GeometryAdmin
* adds fallback DEFAULT_SRID for Geometry model
* adds translations
