Add First Input Option to Improve Performance of Transformers

Related products: FME Form

Probably some of these transformers can be improved about their performance, if they had an option specifying first input (such as "Clipper First" in the Clipper) and the user could control the input order.
AnchoredSnapper: Anchors First
ListBasedFeatureMerger: Suppliers First
NeighborPairFinder: Candidates First
SpatialRelator: Candidates First
LineOnAreaOverlayer: Area First
PointOnLineOverlayer: Line First
Gathering InterestPartially Released