Add ability to query bounding box of features by id

[c-w]

For Fortis we need the ability to look up a feature's bounding box by that feature's id.

This pull request implements that functionality by:

1. Adding a new route to fetch one or more features by id
2. Adding a new include parameter to compute the bounding box in PostGIS and add it to the feature

Sample response (openstreetmap):

[erikschlegel]

LGTM

[timfpark]

Looks great - thanks!