added b+g e-tech ds100 / ws100 meters

[Vogelbecker]

Fix https://github.com/evcc-io/evcc/issues/17105

Hi,

I added both meters mentioned in #17105

Test on my site looks okay:

WS100 (1phase):

mfriedr7@dev:~/github/ev_test$ ./evcc -c ~/evcc.yaml meter

test_ws100
------
Power:          178W
Energy:         171.5kWh
Current L1..L3: 1.27A 0A 0A
Voltage L1..L3: 229V 0V 0V
Power L1..L3:   178W 0W 0W

DS100 (3phase):

mfriedr7@dev:~/github/ev_test$ ./evcc -c ~/evcc.yaml meter
test_ds100
------
Power:          0W
Energy:         66.0kWh
Current L1..L3: 0A 0A 0A
Voltage L1..L3: 227V 226V 229V
Power L1..L3:   0W 0W 0W

(It is correct that it currently shows 0 watts. The meter is connected to the heating element of the heat pump, which is currently not active)