Add support for non-cummulated kWh

[plord12]

The plugin currently return cummulated kWh (total_increasing) ... whilst this is great for the energy dashboard, it makes other uses much harder.

For example I would like to capture carbon footprint .. ie multiplying the current grid gCO2eq/kWh by the current kWh consumption. This isn't easy with cummulated kWh.

Put another way, it should be easy to plot the day's usage in home assistant in the same way as the bright app - see attached.