separate token for the view

use a token with correct type for the fall-back case of using a candidate view as an input.

@slava77  - seems that the proper change here is 

if (enable_)
 tokenPFCandidates_ = consumes<PFCollection>….
else
tokenPFCandidatesView_ = consumes<PFView> …..

[as it is, the first consumes statement is not always right unless I've missed something]