[Feature] Add a default time zone option

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

It would be awesome if immich would default timezone to local (as determined by the server's host system's time zone setting) if a new image doesn't have a time zone that immich can find (comes up (+00:00)), or if there was an option to set a default when it's unknown (if that's easier and/or for those who may not host their own server - family living at a distance).

I have _significantly_ more pics taken at or very close to home that don't have a timezone than I have pics that I've taken while traveling to a different time zone. It would be much more efficient to set the correct TZ for the exceptions than for the rule.

Platform

• Server
• Web
• Mobile