[WIP] Dynamically update stored credentials in mount config

Instead of storing credentials in a session variable, on login the credentials are used to update any dynamic personal mount points (or create them if system-wide ones are encountered) with the new credentials.

Sharing for `SMB_OC` has been enabled.

The following needs testing:
- [ ] iRODS
- [ ] Sharing support (this is a little broken at the moment)
- [ ] Non-dynamic mount points are working as expected

@PVince81 @icewind1991 @DeepDiver1975