add cemetery=grave and historic=tomb

[WlaKom]

Add grave as node (​cemetery=grave; ​historic=tomb) at maximum zoom.
Currently, many graves are mapped in cemeteries, but users do not see them.

[Don-vip]

Tag is documented, used 4000+ times, worldwide, I'd say yes.

[Don-vip]

We would need two presets (one for historic=tomb, one for cemetery=grave).

Found a grave icon:
​https://github.com/osmandapp/OsmAnd-resources/blob/master/icons/svg/tourist/tomb.svg

But nothing free for tomb (mainly used for tumulus, crypts, mausoleums, pyramids, etc.)

[Don-vip]

historic=tomb is now used more than 10000 times in OSM database.

I'm a little bit surprised according to its definition and I wonder if people are not using this tag to map simple graves. "Tomb" may be a false friend in several languages. For example in French, a grave is a "tombe" and a tomb is a "tombeau".

@Klumbumbus: do you have a suggestion for an icon?

[WlaKom]

Similarity of names, but different meanings are common on OSM.
But we are based on the British language.
As I wrote earlier, a very small black square would be completely sufficient. The rectangle would require the direction along the axis. The cross would not be appropriate for non-Christians.

[Klumbumbus]

I tried to create an icon. The rightmost is my suggestion for historic=tomb (15.svg)

[Klumbumbus]

Also the wikipages need some clarification. E.g. the description of cemetery=grave is "To map a tomb."