UI - Implement"thumbprint" visualization on workbook overview cards

[brodavi]

These are visible on the /workbooks page https://stage.pdd.colab.coop/workbooks

.... but instead of the treemap showing on the cards, we are going to show the circular visualization:

[eethann]

Should not include the "reload" icon, just the starburst. The startburst should start with just the total reduction in carbon emissions for the energy sector, the orange band, if reduction for other sectors are not available. @litenull is a good person to consult about this in more detail. Until we have additional sectors implemented in the API this visualization will likely be somewhat incomplete. Feel free to propose revisions!

[fbarl]

I'd like to take a stab at this issue! :slightly_smiling_face:

I noticed that the current treemap is actually a SVG image placeholder - does this mean we should be using starburst placeholders or are they supposed to show some real data (albeit incomplete)?

Assuming the starbust should visualize actual data, I have a couple of questions to kick it off @litenull:

• I'm looking at GET /workbooks endpoint but I'm not sure it contains all the data needed for the visualization; is there another endpoint I should be looking at?
• Is it possible to not have any reductions available (not even for the energy sector)? If yes, I wonder what we should use as an empty placeholder
• I also noticed we use run_button.svg as a placeholder image in the workbook header recalculation button - is that the visualization we want to reuse here and if yes, would it also make sense to replace it there with the real data (perhaps in a separate issue)?