Add area rendering of taxi

[jragusa]

Fixes #3110

Changes proposed in this pull request:
Add rendering of amenity=taxi in a similar way than other parking amenities

Test rendering with links to the example places:
https://www.openstreetmap.org/way/284714637

Before

After

I noticed that amenity=parking is also included into amenity-low-priority in the project file. Should I put also taxi in this section ?

[Tomasz-W]

@jragusa Thanks for this PR! Are you interested in similar case of traffic calming islands #2086 ? It's another one missing street element on map.

[kocio-pl]

Thanks for this contribution!

[jragusa]

@Tomasz-W I will take a look on #2086