Query how any administrative boundary district overlaps overlaps with all other administrative boundary districts.

[lindsaypoirier]

Currently users click on a community board to see which other administrative boundary districts overlap with the community board. Ideally users should be able to select any administrative boundary, see a list of districts within that administrative boundary, select a district from that list, and then see all other administrative boundary districts that overlap with the selected district.

This task will be completed in several steps:

1. Users will select an administrative boundary (e.g. police precinct, school district, or NTA) from a list of administrative boundaries.
2. The code will turn on the layer representing that boundary and turn off all other layers so that users can see which unique identifiers represent the geography they are interested in.
3. The code will query the table representing that boundary in Carto and return a list of the unique identifiers for all districts in that boundary. These will display as a second drop down.
4. Users will select a district within this second dropdown.
5. The code will query each of the eleven shape files stored in Carto to determine which districts in that shapefile overlap with the selected district. These will be returned and displayed in an infobox on the right hand side of the screen.