Battery Spare Capacity control (WebAPI) & Wallbox II-IV data

WebAPI: Set the 'battery spare capacity' (developed by @debug-io)

• Disabled by default (you need to enable it via the GUI)
• The code has been adjusted, so that this value will be only "updated in HA" every 24h and only if the new control is active
• Obviously this feature only make sense, if you own the corresponding Technic-Package

LocalPolling: Wallbox II-IV Support

• implementing #25 (and make use of USE_L1-L3 flags)
• Querying data (from SENEC.Home device) of activated Sensor only (reduce the load) (like wallbox, bms or fanspeed data)

NEW in test-007

• FIXED Inverter Integration - OMG!