Feature Request: Heating summary #801

Hi, since a couple of month energy consumption data is properly supported by my Vitocal/API. Today I found out how to
read the heat production values.

Probably you can add this values directly to the device object.

code by google and some reading of the full dump of my device [json_data = json.loads(device.dump_secure()]:
properties = device.service.getProperty("heating.heat.production.summary.heating").get("properties", {})
heute = properties.get("currentDay", {}).get("value", 0)
monat = properties.get("currentMonth", {}).get("value", 0)
Jahr = properties.get("currentYear", {}).get("value", 0)

BR hufnala