[Feat.] Timezone selector

[WEBudoGT]

Is your feature request related to a problem? Please describe. Notification body including timestamps will always produce them in server's timezone (GMT in my case).

Describe the solution you'd like As notification body is based on the same "EmailNotification Template", and Email notifications are timezone configurable, I guess a dropdown with timezone selector could be possible to implement. It would be great to have this option.