collapsible filter lists in footer

[eharkins]

Makes lists of filter options in the footer collapsible (or rather expandable since they are collapsed by default); see nextstrain/ncov#738 (comment) for motivation for doing this.

Uses https://www.npmjs.com/package/react-collapsible similar to the situation report listings on https://nextstrain.org/sars-cov-2.

Maybe it would be better to just use a traditional dropdown (as the color by does in the sidebar) rather than this special collapsible component - when interacting with it, I'm not sure what it gives us in terms of a good user experience that a regular dropdown menu does not. Maybe being able to see all options at once listed next to one another? Or being able to see which ones are selected while you are looking through options? Interested in feedback on this!

[emmahodcroft]

I actually think this works well. I like that it brings the very bottom of the page (which has pretty critical things like the download and the citation) "up higher" so that hopefully they're easier to see - I don't blame anyone for currently stopping scrolling during such a big chunk of blue text!

I think being able to see all the filtering options is actually still pretty useful, and being able to see which filters are applied. I'll admit this isn't quite as useful anymore, with the new filter type-in box, but actually in trying this out I realised it's faster (at least for me) to filter multiple clades by using these than typing, since I can click much faster than I can type!
So I think this is a nice compromise between maintaining the old usability but in a much more compact style.

However, would be curious to see what others think!

[jameshadfield]

Thanks @eharkins - this is much nicer. I tweaked the styles a tiny bit. I plan to merge this shortly.