Enable or facilitate support for EVCC

[hyperbart]

It would be nice if SmartEVSE could be made compatible with https://github.com/evcc-io/evcc .

EVCC would act as a charge controller so you don't have to put clamps in and it does this by combining all metered devices (solar inverters, digital meters etc) and combine this with the SoC of a car to efficiently charge one or multiple cars.

[hyperbart]

Duplicate, this issue should have been posted at V3.