Refactoring modelType() out of FluidProperties class
Refactoring modelType() out of FluidProperties class

This is RELAP-7 specific. The FluidProperties system will be moved into
a MOOSE module and there is no place for modelType() there.

Refs idaholab/relap-7#19688
sapitts/moose,lindsayad/moose,idaholab/moose,idaholab/moose,lindsayad/moose,milljm/moose,milljm/moose,laagesen/moose,jessecarterMOOSE/moose,lindsayad/moose,laagesen/moose,lindsayad/moose,laagesen/moose,andrsd/moose,andrsd/moose,laagesen/moose,dschwen/moose,jessecarterMOOSE/moose,sapitts/moose,andrsd/moose,milljm/moose,jessecarterMOOSE/moose,bwspenc/moose,jessecarterMOOSE/moose,harterj/moose,jessecarterMOOSE/moose,lindsayad/moose,bwspenc/moose,dschwen/moose,harterj/moose,harterj/moose,harterj/moose,sapitts/moose,dschwen/moose,bwspenc/moose,idaholab/moose,dschwen/moose,milljm/moose,idaholab/moose,andrsd/moose,dschwen/moose,idaholab/moose,laagesen/moose,andrsd/moose,bwspenc/moose,sapitts/moose,harterj/moose,milljm/moose,sapitts/moose,bwspenc/moose