Change the way adding occurrences through Locality -> Occurrences tab works

[juhanikat]

My current idea is:

1. User navigates to Locality -> Occurrences tab
2. User clicks the "Create new occurrence" button
3. User is navigated to "occurrence/new" (in a new window)
4. User creates a new occurrence normally, the locality field is automatically filled and cannot be changed
5. After saving the new occurrence, the Locality -> Occurrences tab is updated automatically with the new Occurrence, and the editData of the Locality is updated to include the new Occurrence/Species (is this possible to do?)

This doesn't work if the user is trying to create an occurrence to a new locality, since the locality field cannot be automatically filled in that case, since the locality does not exist yet.