add current power comsumption sensor

[s-kurz]

adds the sensor for the current power consumption given by Unknown_Calculation_268

[rhammen]

@BenPru @s-kurz
After I installed 2024.10.05-Beta, I now get the errors below in the logs.
Looks like this calculation also need a minimal firmware version.

min_firmware_version_minor=FirmwareVersionMinor.minor_80,
(or minor_88 ?)

==============================
This error originated from a custom integration.

Logger: custom_components.luxtronik2
Source: custom_components/luxtronik2/common.py:58
integration: Luxtronik
First occurred: 20:50:34 (2 occurrences)
Last logged: 20:50:34

Get_sensor Unknown_Calculation_268 returns None

This error originated from a custom integration.

Logger: Luxtronik.Calculations
Source: custom_components/luxtronik2/common.py:52
integration: Luxtronik
First occurred: 20:50:34 (2 occurrences)
Last logged: 20:50:34

Calculation 'Unknown_Calculation_268' not found

[s-kurz]

I added the minor_88 since its the version used with the energy sensors