Add support for solar generation totals (not just instantaneous)

[mcolyer]

Is your feature request related to a problem? Please describe.
No.

Describe the solution you'd like
I'd like to see how much power I've generated today, not just the current output of the array.

Describe alternatives you've considered
I tried using the sum integration but it doesn't seem to work properly.

Additional context
Here's a screenshot showing how the estimated solar production integration looks and the Tesla solar report directly above it:

[alandtse]

Since we would literally be implementing the integration component, it doesn't make sense to do our own version. Also, we return what the Tesla API returns. If there's a problem with the integration integration, please report to them.