Web UI: Display current Contactor-2 state

[Hermarcel]

It would be nice to have an indication in the WebUI for the state of Contactor-2. It helps while figuring out if the car or the EVSE is limiting charging to single phase.

For the WebUI it could be something like:

Current UI:
Contactor 2: Auto

Proposal:
Contactor 2: Auto (now: ON)
or:
Contactor 2: Auto (now: 3P)

Edit: request to add to mqtt removed: It seems that "NrOfPhases" already does this.