Updates map specs
Adds search filters

Adds removable search filters to search options area.
Set SMC service area and Human Services kind filter as default on first search

Adds hidden fields to homepage search box to set default filters on
first search.
Removes categories

The categories are aggregated elsewhere in the layout in
https://github.com/codeforamerica/human_services_finder/pull/290, so
this commit removes them from this branch.