Prompt warning or ask conformation while removing devices from the application

[sumitshinde-84]

Description

Removing devices from the application should prompt a warning or ask for user confirmation, as the user will lose all their previously done work if they remove the devices.

Which customers would this be available to

None

Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate

[Steve-Mcl]

NOTE: for who ever picks this up.

There was a lot of detail in the slack thread that help us understand why this occurred. As that is not visible here and may get lost, the short version is Sumit was moving devices from one place to another and the only option available was to unassign then reassign. This is what caused the devices to flip back into fleet mode and consequently delete his work. It was noted that we may want to revisit that particular behaviour.

Also note, once bulk move operations are introduced, this will be less of an issue when moving devices between applications.

REF: https://github.com/FlowFuse/flowfuse/pull/4336