Add Derived Sensors - Provides Inverter and Battery Models

[JensenNick]

To keep things clean, now that I've split the input file into PEES and STAT, I'll only add the derived sensors relevant for PEES in huawei_solar_pees_input.yaml file.

[JensenNick]

Any information about the naming convention used for iStore products? What would the output of {{ device_attr("sensor.inverter_input_power","model") | regex_findall_index('(SUN\d+-\d+KTL-[L|M|MB]\d+)|(IS-HYB-\d-\[1|3]PH)', 0) | first }} be?

[JensenNick]

With the naming schema "IS-HYB-12000-3PH" for the iStore products, how do we distinguish between M1, MAP0 and MB0 inverters which are all 3PH?