Reset whole EVSE by C++ API call

[matth-x]

The OCPP specification demands a complete reset procedure for the whole EVSE. Jeremy already told me that this is already possible via RAPI call but should better be implemented via C++ API call. For the ESP32 itself, it's no problem to use ESPAL.reset().

[jeremypoulter]

C++ API for restarting the EVSE module implemented via #618

[jeremypoulter]

@matth-x Do you want to use this ticket to implement the OCPP bit when merged or is there another ticket for that?

[matth-x]

@jeremypoulter I'm planning a cumulative update which will also address the new reset function. Since the requested feature is done, I'm closing this ticket, thanks.