Add available current per phase to settings

[philipostli]

Want to add possibillity to change available current on each phase in settings.
Now it is only available as a action card.

Check if possible to change per phase on Go cahrgers, as in the app all three are controlled simultaneously and one user reports that only lowest value is used when setting 16/16/13 on a Tesla. In portal settings for individual control is available, but need to test.

Capability only shows lowest (or highest) value.

[philipostli]

Also check if they can be hidden, when charge mode is not "Standard", as it can not be changed in Automatic or eco-mode.