* changes SimpleGeomForm behaviour on small geometries (<1m²): These geometries will now be dismissed on processing
* adds a new info message in case of automatically removed geometries on saving
* updates tests
* adds clamping of 3D geometries to 2D geometries if uploaded using the map importer
* extends tests for payment-document linkage
* fixes bug in team-admin selection where autocomplete could not be resolved properly
* adds geom back writing to form field in case of invalid geometry, so the invalid geometry will be shown again
* updates tests
* fixes bug where race condition of celery workers could lead to duplicates in parcels (needs migration)
* adds team sharing field to share form
* splits sharing logic into user based and teams based
* adds TeamAdmin for admin backend
* adds validity check on Team name -> only unused names shall be valid
