New advanced search UI

 - Based off a general styling/prototype branch mtedeschi/OTM2/topic/map-page-prototype
 - Cleans up the search templates and filter object generation by adding an `ISNULL` predicate
 
Notes:
 - Styling is needed on the plot detail page (the new subheader pushed the content down)
 - Styling is needed on the "Detail Filters"
 - This does not include stewardship searching or the "Display Filters"