Feature: Create area

The command to create an area exists in the API, however it is not accessible via the UI.

Add the possibility to create an area - for moderators only, via the top green (+) button. One should be careful dealing with the geometry, and it should be associated with a reindexing process to ensure that all data is available when filtered by the new area.

The request is low priority for just the button, as areas are very rarely created, but the reindexing part is blocking at the moment and would save a lot of energy.