[Feature] Add visual indications for missing programs or exceptions

[laurensvalk]

Situation: Primehub (early V4) has some programs loaded and I want to start one of them with the center button. But nothing happens.

Would it be nice if there was a visual indication that shows there is a program loaded and was started but had an error.

By example: The program uses bluetooth but bluetooth has been switched off.

In fact a visual indication to differentiate between:

• there is no program loaded in this slot,
• there is a program but failed.

Not a very urgent matter, but thinking of coaches and young users.

Originally posted by @BertLindeman in https://github.com/pybricks/support/discussions/2366