Render topicmap topics with maptype-specific icon
The maptype-implementer provides a maptype icon.
All webclient components use this icon when rendering a topicmap instance:
- topicmap selector
- on canvas
- in topic lists
- search results
- Related tab
Maybe this is an issue too complex to be included in 5.0.
If included it will be a breaking change.
Maptype implementations will require adaption.