Add ability to view yearly consumption

[ErikThorsell]

The following three views are added:

• Last Year: Show consumption for the previous year (YYYY-01-01 to YYYY-12-31)
• This Year: Show consumption from the beginning of this year to today
• Running Year: Show consumption for the past 365 days

[ErikThorsell]

@dhogborg, I was a bit hot on the porridge and did not see #26 and your comments there.

Testing this PR locally, I don't seem to have any issues, but maybe I'm missing something obvious with the API?