Number of species reported by `atlas_species()` differs from `atlas_counts()`

[mjwestgate]

Main issue is here as the problem is primarily server-side; but basically nrow(atlas_species()) differs from the number returned by atlas_counts(type = "species") in some circumstances.

Proposed solution (documented here) is to add flimit=-1 on the call from atlas_counts().

Initially reported by @shandiya