* Add mysensors IR switch device and service
* Add MySensorsIRSwitch as child class to MySensorsSwitch.
* Add platform specific service mysensors_send_ir_code. Only call
device method in service function if device is IR device.
* Add service and required attribute to state helper to support scenes.
* Move V_IR_SEND type from sensor.mysensors to switch.mysensors
platform.
* Populate switch.services.yaml with service descriptions.
* Fix check of entity_id in service function
Since multiple entity_ids can be passed as service data, and the
entity_id service attribute is forced to a list by the service
validation schema, the check in the service function should iterate
over any entity ids.