* adds Revocation model to interventions/models.py
* adds revocations to interventions detail view
* fixes duplicated ids in html includes
* refactors controls for detail view into included template files (controls.html)
* reduces max length for payment transfer notes from 1000 to 200
* adds RevocationAdmin to intervention/admin.py
* adds new form for adding a Revocation to an intervention's legal_data
* only one revocation per intervention possible
* removes add button in case of an existing revocation
* adds revocation routes to intervention app
* renames document field in Document model into file for more clarity
* adds/updates translations
* adds help texts to add payment form
* adds removing button for payments
* refactors user fetching into BaseForm
* adds generic RemoveModalForm which is intended to be used for every modal form which shall remove something
* adds translations
* removes unused html
* prepares payment amount field to be able to process german inputs like '1.000,50' which is not the international default
* 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
