[Feature]: Flutter flavors

[Mortein]

Feature detail

Add a Development/Debug flavor to the Flutter app. Appends the non-production name to the app id (app.alextran.immich would become app.alextran.immich-dev). https://docs.flutter.dev/deployment/flavors

Allows more than one version of the app to be installed at the same time, such as the production version and a development version, as they no longer share the same application ID. I know this works well on Android, not sure about iOS sorry.

Not sure if there's a Test/Beta version as well, but that could be a third flavor.

To make it easier to tell them apart, use a different icon for each. Maybe the standard Immich logo, but with progressively fewer coloured petals from each layer (Production->Test->Development/Debug).

Platform

Mobile App

[alextran1502]

Love this one!