Import and display action scorecards scores for local councils

[struan]

Splits it into two datasets: total and section scores.
Updates the area template to allow range related datasets.

Fixes #514

[struan]

Not clear if the chart needs a title, possibly so.

[zarino]

This looks generally ok to me. Three points:

• Ideally, rather than comparing to a "UK average", we’d compare to all councils of the current council’s "type". But I expect there’s no way to easily do that right now. So, as a minimum, I think we should hide the "UK average" stuff everywhere in relation to this data (so, on the area page card, and on the Explore page) – both because comparisons to the average mean less when different councils have different powers/responsibilities (and even different maximum possible scores per section) and we also said to council officers, in the run-up to the Scorecards, that we wouldn’t facilitate comparisons outside a council’s "type".
• On the area page card, my instinct is a table (without the js-chart class) would be easier to read than a chart. What do you think?
• I’d title the card "Council Climate Action Scorecard" rather than "Action Scorecards overall score"

[struan]

Tweaked:

[zarino]

Two quick comments on things I’ve just noticed (sorry!)

I also wonder what’s going on with the rounding in your screenshot?