* adds model and form mixin for PIK
* integrates mixins for compensation, ema and ecoaccount
* adds migration files
* extends API
* extends API test data
* adds is_xy fields to compensation, ema and ecoaccount reports
* adds is_pik information to detail views
* adds/updates translations
* adds geometry-remerging with former deductions
* adds geometry-area calculation
* adds fallback for old data migration on deprecated biotope code lists
* fixes typo in CODELIST_AFTER_STATE_BIOTOPES_ID
* changes action_type from ForeignKey into M2M
* adds migration
* changes form widget
* WIP: changes rendering on detail view of compensation
* TEST NOT CHECKED YET!