Show off-street parking facilities

[mdejean]

• Add DCA-licensed off-street parking facilities

https://data.cityofnewyork.us/Business/Active-DCA-Licensed-Garages-and-Parking-Lots/a7m8-iids

• Estimate non-public parking from PLUTO's GARAGE_FLOOR_AREA

https://github.com/NYCPlanning/db-pluto