Area Card should allow cherry-picking of entities

[flz]

The new Area Card automatically aggregates all entities within given domains to allow quick actions.

There should be support to cherry-pick specific entities as well.

Specific examples:

• Pool Area has a bunch of switches, I only want the main pool pump to be turned on and off through the switch icon.
• Bedroom has a bunch of smart switches but I don't want them to be turned on and off that easily (could happen by mistake) or I only want a subset to be turned on/off.
• Kitchen has a smart switch for the dishwasher/fridge/... which you don't want turned off through the switch icon.