Add rendering for healthcare=rehabilitation

[HolgerJeromin]

Expected behavior

Rehabilitation clinics are no hospitals so should not have a hospital tag.

There are rehabilitation elements on buildings and campuses which could both get a healthcare dot.

Actual behavior

No rendering in the campus scenario.
If the element is on a building it gets a name.

#3731 reverted a buggy version of a generic healthcare rendering.
But we got no new open issue for readding this features again.
We could also reopen #2938 instead, but we have some special issues #4235 and #4402 open.

[imagico]

Currently 2881 uses, used both as a primary tag and as a secondary tag, the latter together with amenity=clinic/hospital but also with amenity=social_facility/nursing_home and others.

Semantics of the tag are fairly unclear - the practical implementation of the concept of medical rehabilitation and the terminology used differ a lot in different parts of the world and the wiki does not specify any generic language independent criteria. In many languages at least some rehabilitation facilities are called clinic, hospital or similar terms in that language (like Reha-Klinik in German).

The wiki page recommends specifying healthcare:speciality=* for clearer meaning, this is currently done in a bit more than 400 cases. But even with that the scope of the tag can still cover an extremely wide range from something like a small facility for ambulatory physiotherapy of a single patient at a time with a staff of one or two to a huge inpatient facility with hundreds of beds.

[BertMule]

I am also dealing with this issue for a large healthcare ground, which isn't visible at all. No marking, no boundary, no name.

https://www.openstreetmap.org/#map=17/52.10753/4.71621