* splits Intervention model into main components
* Compensation (main object)
* ResponsibilityData (holds organizations and handler) - same as used for intervention
* This way data can be extended more easily in the future
* refactors deadlines
* moves accessibility of compensations completely into related intervention.users set
* this way the visibility for a compensation can not differ from the one of the 'parent' intervention
* adds related object overview in detail view
* adds comment field to payment model for 'Verwendungszweck'
* simplifies intervention urls
* adds translations
* adds user access relation to certain models
* adds pagination to tables
* adds checked_on/_by attributes to intervention model
* adds custom column rendering for checked and registered columns
* adds first simple index filtering of default interventions for user
* adds translations
* No detailed permissions due to django constraints on model-based permissions
* instead: logic controlled permission by group membership
* adds translations
