WishlistEntityTrait (currently in the HookHandler namespace but to be moved to the root in r1207008) is what does our rudimentary process caching at the moment. This is fine for now, but won't scale, particularly for T406957: Show wish titles on lists (like on Wikidata).

We should make use of ChangesListInitRows to prefetch the entity titles en masse on change lists, as opposed to one at a time. Something similar to Wikibase's LabelPrefetchHookHandler.

Additionally, we might want to look into a more persistent cache than just for a single-request. Particularly during Wishlist promotional campaigns, we'll likely get more cache hits than misses. The TTL could be configurable to accommodate for variable needs.