Define interaction of, and style the election lookup map

[jenniferthibault]

Rudimentary maps available here: https://fec-dev-web.18f.gov/elections/

The only interaction we have for the maps on the lookup page so far is that you can click on a district to search on that district

There’s also currently no way to go back to the map with all possible districts filled out once you’ve searched.

The maps also need some styling: possible variables include but are probably not limited to district labels & colors.

Steps forward

• @noahmanger to define interaction (w/ help from @onezerojeremy ?)
• @jenniferthibault to propose style
• @jmcarp to consult, review & help implement (?)

[jenniferthibault]

This should take into consideration the differences already proposed in the page interactions in #471

[jenniferthibault]

This is covered mainly by #471 with bits and pieces of #596