Add ability to fetch statistics by bounding box

[HenryGeorgist]

use nsi api to fetch statistics by bounding box.

https://nsi-dev.sec.usace.army.mil/nsiapi/stats?bbox=-81.584180,30.251650,-81.581610,30.251650,-81.581610,30.269390,-81.584180,30.269390,-81.584180,30.251650&fmt=fs

the stats endpoint is not stable, and will be changing, but we will want to capture that return and display it in a pie chart or a bar chart.