Change the way adding occurrences through Locality -> Occurrences tab works #1240

My old idea was:

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.

Now I'm trying to make it work so that when the user clicks the button to create a new occurrence, it opens a popup window where you can create a new occurrence. Then the user can close it and finalize the locality normally, and the occurrence is created at the same time. This should also work when the locality is being created for the first time.