Remove alarm panel group

[bemble]

Alarm group should be handled using alarm template. To handle when panels have different state and display it in the card, we should handle partial states: partially_armed, partially_disarmed etc.

[piitaya]

I think we can add a list : "warning_states" to allow custom warning states (because partially states are not official). Or we just use split("_") 😂

[bemble]

Problem value_template can only return one of those states: armed_away, armed_home, armed_night, arming, disarmed, pending, triggered and unavailable (the doc).

Every other state such as partially_armed will set state to unknown. And there is no way to add custom attributes to the entity. So custom state is not the way to do.

[bemble]

Another way to do it, and I think that's the best, is to allow user to add alarm panels in a list in the panels configuration and use this list to check if all panels have the same state. This is way cleaner, it won't use any unofficial state or any other tweak.

What do you think about this solution @piitaya ?

[piitaya]

Do you have any desync issue with alarm templates ? May be you can just add a card or a chip to show that there is a problem ?
I think that not a problem solvable with mushroom.