Applied naming conventions to density, momentum, energy
Applied naming conventions to density, momentum, energy

Refs idaholab/relap-7#453

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