Reduce HGC rechit memory footprint

Remove a merging module that is un-necessary, should reduce HGC rechit memory footprint by 2x.

Trying to get a working rechit creator that can service all three HGC subcomponents at once, removing the need for a merging module. For some reason it will not let any rechits pass. 

This is a decent patch for now since the subcomponents are clustered separately.

@pfs @vandreev11