CategoryTeaser icon: automatically choose fitting icon for categories without wikidata image

[nylki]

Currently the SFSymbol "tag" is used for all these cases to fill the background. It would be nice to choose fitting icons with some heuristics.
Eg. check in the order, use the first match:

1. if category has wikidata item but no image -> use P31 (instance of) to check against a list of defined Q-items (eg. Q860861 (sculpture) -> "person.bust" or "photo.artframe")

2. check category name (eg. "streets in Paris") for a list of substring or regex matches. This should work for many categories that are lists, since they follow naming conventions.

3. same as (2.) but use the wikidata descriptions and aliases as fallback if no results yielded.

4. ....

5. fallback to "tag" SFSymbol