historic=memorial and tourism=artwork conflicts

[Janjko]

There is a problem with tags tourism=artwork and historic=memorial. They have subtags with the same meaning: artwork has artwork_type=sculpture;statue;bust and memorial has memorial=sculpture;statue;bust. A bust icon is rendered if you put historic=memorial+memorial=bust. But if you add tourism=artwork on the same node, it is rendered like a generic artwork . Even if you put:

historic=memorial+memorial=bust+tourism=artwork+artwork_type=bust

it still doesn't render a bust.
In reality, all memorial=bust are also tourism=artwork, so it isn't wrong tagging.

In my opinion we should first decide which tag is stronger in case of different values, memorial=* or artwork_type=*. After that, just render whatever is in those tags, or in the stronger tag if there are both.

[kocio-pl]

It is documented on the wiki, so I think it's also worth rendering:

https://wiki.openstreetmap.org/wiki/Key:artwork_type

It might be good to also review other types of artwork by the way.

[jragusa]

Bust and stone are concerned. I propose to render for now artwork_type=bust with the current memorial=bust icon. It's a rapid fix. Icon of memorial=stone suggests an inscription so I propose for this one to wait for the rendering of natural=stone as node (#2616).

[geozeisig]

Using the icon for an entire building was for me confusing. This happens when artwork_type=architecture is applied. An example is the Siemens-Villa. Maybe you should make an exception for artwork_type=architecture.

[jragusa]

@geozeisig good point. Why not the upper part of a greek column of Ionic order as icon for artwork_type=architecture ?