Describe the bug

If the frontend gets an unexpected Island mode from the backend (not "advanced", "ransomware", or "unset"), the configuration page crashes.

To Reproduce

Steps to reproduce the behavior:

1. Run the Island with any mode.
2. Modify the mode field in simulation_state.json (in the data directory) to something other than "advanced", "ransomware", or "unset".
3. Go to the configuration page on the Island.

Expected behavior

It shouldn't crash and should probably default to "unset" if the mode isn't recognised. This should be changed in the backend. If the mode is not recognised, the endpoint should return "unset". If this seems more like something that the frontend should handle, we should add the condition to the logic to set the mode as "unset" if it's not recognised.

Screenshots