Allow Leaflet Map to query back a Views (or Facet?)

[DiegoPino]

What?

As discussed with @patdunlavey we can extend the work on #140 by adding

• A new Field Wrapper to Search API that allows us to pass geographic data to Solr + config. Like what we do with HOCR.
• A new option in the Key Name providers that can expose lat/long as the proper Data Type that will need that field wrapper
• A new Query Filter type that allows us to search via Solarium that data using lat/long passed from a map (or boundaries)
• An Exposed Filters option (code) for Views so that data can be passed as exposed arguments to a Views (Query -> where -> argument)
• JS that can change the Query Argument means Map communicates back via Ajax, like a Facet would do. Basically the Map becomes a facet!

[patdunlavey]

Hi @DiegoPino thanks for thinking this all the way through to an implementation strategy! I'm not 100% clear about what behavior we are looking to provide on the front end that generates these requirements, so adding that to the issue description would be helpful.

The first four bullets sound like you have a clear handle on how to implement? The final one (JS behavior - that lazy-loads new points as needed?) sounds pretty hard. I googled around a bit and didn't find anything helpful.