Refactor LookupNames#add_immediate_subtaxa to build query
Refactor LookupNames#add_immediate_subtaxa to build query

See @pellea suggestion at https://github.com/MushroomObserver/mushroom-observer/pull/1062#discussion_r912628868

MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer