Follow-up from "Tests for new functor to access Hlt1 TIS/TOS information"

The following discussion from DaVinci!771 (merged) should be addressed:

• @erodrigu started a discussion:

  This very useful comment reminds me - I believe the functorcollections module is not totally clear about the nature of the collections it provides, meaning some are candidate collections, other event collections as it were. We should improve the documentation to make these differences super clear, @amathad and @oozcelik.