Make aspects more useful for higher-level concepts

[Daniel-Mietchen]

e.g.
https://tools.wmflabs.org/scholia/topic/Q15 (Africa)
currently shows basically no papers on things not tagged Q15, but one would expect topics like Kenya, Nile, Sahara or Kilimanjaro to pop up.

Conversely, Faerûn (Q2622787) pops up as related, which is irritating at best.

I know we're running into timeout limits when we try to aggregate across large topics, but we can probably do a bit better than what we currently have.

[Daniel-Mietchen]

On the other hand, the "recent publications" panel at
https://tools.wmflabs.org/scholia/topic/Q46
times out