Quitting Clippi prematurely should restore OBS filename format

[vinceau]

If recording is in progress and Clippi is closed, the OBS filename format is not restored, likewise if the program is force quit or if it crashed.

We should add a hook which detects when the Electron app is about to be closed/quit and send a message to OBS to restore the filename.

This method won't be able to handle crashes or force quits however. We could restore the most recently backed up filename format on first boot, however that is not guaranteed to be up to date and the user may have changed it between now and the last time they ran Clippi.

[vinceau]

Closing this as won't fix. Setting the OBS filename is too finicky in general. Instead we just add a warning that this is an experimental feature and that users should use it at own risk. Added the option and the warning in 3356bc2.