Changed connection format for core channels and heat exchangers
Changed connection format for core channels and heat exchangers

Refs idaholab/relap-7#387

jessecarterMOOSE/moose,laagesen/moose,milljm/moose,lindsayad/moose,andrsd/moose,idaholab/moose,jessecarterMOOSE/moose,milljm/moose,sapitts/moose,lindsayad/moose,laagesen/moose,jessecarterMOOSE/moose,sapitts/moose,harterj/moose,harterj/moose,idaholab/moose,andrsd/moose,bwspenc/moose,dschwen/moose,idaholab/moose,lindsayad/moose,sapitts/moose,sapitts/moose,lindsayad/moose,milljm/moose,bwspenc/moose,andrsd/moose,milljm/moose,bwspenc/moose,harterj/moose,harterj/moose,idaholab/moose,harterj/moose,jessecarterMOOSE/moose,dschwen/moose,dschwen/moose,dschwen/moose,andrsd/moose,milljm/moose,idaholab/moose,laagesen/moose,bwspenc/moose,sapitts/moose,laagesen/moose,andrsd/moose,jessecarterMOOSE/moose,laagesen/moose,lindsayad/moose,bwspenc/moose,dschwen/moose