Highly experimental pre-release with implementations mostly focusing on mts300 thermostat.

features

• added support for mts300 basic thermostat functions (#557). Still missing some features (like fan/humidifier control) this should at least get up and going with basic thermostat control. It features heating, cooling and heating/cooling HVAC modes with temperature setpoint(s) control.
• enriched the diagnostic feature to better 'brute force' some newer namespaces not yet correctly known (trying to get insights on #517)