At least one other collaborator is registered in Keycloak.
Main success scenario:
The map creator chooses if the map is open to be viewed by every registered user or member (public/protected/private).
The map creator searches for collaborators by their name.
The map creator adds a collaborator found before (repeated as needed).
The map creator can create alternatives of existing layers and designate which can be edited by collaborators.
Alternative scenario:
The map creator removes a previously added collaborator.
Error scenario:
The app can't send an invitation to a requested collaborator through network issues.
In this case, the map creator should be informed by an error message and is prompted to try again.
Postcondition:
Collaborators can modify the map like it is one of their own.