Indicator summary in GHSCI web app should display table with plain language variable names

[carlhiggs]

Is your feature request related to a problem? Please describe.
When clicking on an analysed area to view a summary of its indicators in the GHSCI web app, this displays a leaflet pop up with the variable names and values as they appear in the data (except with rounding).

That's useful, but only to a point. In the above image what is 'E_EC2E_T15', and what are the units its measured in? You'd have to look in the generated data dictionary CSV or XLSX to find out that is a linked covariate representing "Total emission of CO2 from the transport sector, using non-short-cycle-organic fuels in 2015" (side note -- that is just description, but without units; those should be described too)

The full text wouldn't really fit in the leaflet pop up, which is already cramped. But it could fit in a table within a nicegui dialog window.

Describe the solution you'd like
Rather than pin indicator data on each feature in Leaflet, could just use the area ID and return this when clicked with a callback that when received is used to retrieve and format data in a dialog window table. I suspect this would be more efficient, as well as better formatted.

It would involve using a lookup (probably drawing on the data dictionaries files/methods) to get the descriptions rather than variable names -- or just append the values to the data dictionary in a displayed table.