Fix broken DT inverter

Add new 'inverter_type' configuration parameter.

The type (and communication protocol) of inverter can be detected automatically, but it is generally recommended to explicitly specify the inverter_type to improve startup reliability and performance.
One of ET, EH, ES, EM, DT, NS, XS can be specified

Add new 'include_unknown_sensors' configuration parameter.

There are many values reported by the inverters whose meaning is not yet fully known. Those sensors are named "xx*" and will be provided if the include_unknown_sensors parameter is set to true.
The default behavior was changed and xx* sensors are no longer provided by default !!!

(+fix broken DT inverter)