Support the state_color flag on entities card

[hufman]

The entities card has a flag to enable the yellow color when entities (such as sensors) are "on". This flag is just part of the card definition: {"type":"entities","entities":[{"entity":"light.patio_sw"},{"entity":"light.hue_smart_plug_1"},{"entity":"binary_sensor.front_door_instant"}],"state_color":true}