Use latitude and longitude in url

[pjdufour]

First...

• I've made sure there are no duplicate issues

Issue type

• bug report
• feature request

Problem

Urls are really long.

http://localhost:8080/queries/chinese_food_geojson?extent=-88731818.53311718,4705346.075299296,-88718766.91053748,4707257.001006425

Proposed Solution

Instead of dumping the webmercator extent to the url, pass through a filter to construct a lat long bbox with 5 decimal places.

Risks/concerns

Complexity. Slightly slower to update/read. Nothing significant as OpenLayers has internal functions supporting the conversion.