Add Copy-Constructors for more CustomPropertyProviders.

[nightm4re94]

With 50040a373e060fd97497e4b0a9996fc688e2652f, we've introduced Copy-Constructors for the abstract types CustomPropertyProvider and Property, as well as Layers, MapObjectLayers, and MapObjects.

In an effort to unify how the engine handles cloning, we should consider adding more of these Copy-constructors to the CustomPropertyProviders Map, Terrain, Tile, and maybe others as well.

• [ ] Map
• [x] MapImage
• [ ] Terrain
• [x] Tile
• [ ] Tileset

[werlikth]

Hi, Is this still and active issue and is anyone working on it? Otherwise I and some student partners would like to look into this issue.

[nightm4re94]

this is still open, yes. Feel free to implement it!