Include more Gen1 registers

[karlbeecken]

Hi,

I did some reverse-engineering and found some more read registers that can be used on my BK1600 Ultra.

There are:

• two new for realtime control: READ_REALTIME_CONTROL_ACTIVE and READ_REALTIME_TARGET_SOC
• new AC info: NET_AC_POWER as a signed value of incoming/outgoing AC power, AC_CURRENT as a signed value for the incoming/outgoing RMS current, and AC_OUTPUT_ACTIVE that shows if the output is being used
• two for grid voltage and frequency on Gen1 devices: VOLTAGE_GEN1 and FREQUENCY_GEN1
• two for the entire battery pack's voltage and current (current is also signed): DC_VOLTAGE and DC_CURRENT
• two thermal sensors with unknown positions in the device, maybe related to the controller board: GEN_1_THERMAL_1 and GEN_1_THERMAL_2

As I don't have access to a Gen2 device, I could not test if these registers are also available there. If not, it might make sense to mark them as Gen1 only somehow, so consumers can easily recognize what they can and cannot use for a given device.