Microwaves (combi and plain) were routed onto the oven registry (issue
#121), which meant entities carried oven-flavored keys (oven_state,
oven_mode, oven_setpoint) and inherited oven-specific behavior that's
wrong for this family: a 30-270C setpoint range instead of this family's
actual 40-200C, a cooking-mode list missing MicroWave/MicroWaveGrill/
MicroWaveConvection/KeepWarm entirely, and a lamp switch that read/wrote
the oven's 'UpperLamp' option token instead of this family's 'Lamp' token.
Adds a microwave device type (by_type/microwave.py,
capabilities/microwave.py) that reuses the oven board family's shared
operational-state/door/connected/recipe-cook capabilities but defines its
own cooking-mode, setpoint, and cavity capabilities with the corrected
bounds/vocabulary, plus a new power_level sensor for the cavity's Watt
setting that was previously unexposed.
