Charge now duration

[VIDGuide]

added support to show remaining duration of active Charge Now.
Shows Date/time, and minutes remaining, as well as the currently set amps.

Desktop:

Mobile:

[ngardiner]

This is great @VIDGuide, although I would move the presentation logic from getStatus to the JavaScript. Whilst we do use getStatus from the web front end, it's also a REST API call and could be used in another web template or in a separate app, and they would have to parse the text (eg Currently: ) to get the raw value.

[VIDGuide]

Good point. I'll submit an update in a little bit.

[VIDGuide]

PR updated now with changes. API now returns chargingAmps and chargingEnd as raw values (ints in both cases)
JS now processes and formats those into displays.

Note: One potential issue could be if the browser and server are in different timezones, the "minutes remaining" calculation may be incorrect. May need to look at returning the diff as a 3rd value in the JSON to solve that.