Don't forget about scheme name

[dabreegster]

A few requested changes:

• Emphasize scheme name, not the reference, in the sidebar. Most people don't know the reference offhand.
• Stop showing "scheme X has 4 features." That's not useful to anyone.
• Add a free-text filter for scheme name or reference

Before merging, I want to see if scheme name is ever blank, because then the SchemeCard title will be hard to click. We could fallback to the reference? Or maybe this never happens; we can assert in aatip-scheme-data and update the TS if so.

Demo: https://acteng.github.io/atip/browse_show_diff_stuff/browse.html

[dabreegster]

jq '.schemes[] | .scheme_name' all_schemes_output.geojson shows we have scheme name for everything, actually! So I'll merge this now so because can start using it, and follow up by updating the TS definitions and asserting this remains true in atip-scheme-data