GeometricField: Renamed internalField() -> primitiveField() and dimensionedInternalField() -> internalField()

These new names are more consistent and logical because:

primitiveField():
primitiveFieldRef():
    Provides low-level access to the Field<Type> (primitive field)
    without dimension or mesh-consistency checking.  This should only be
    used in the low-level functions where dimensional consistency is
    ensured by careful programming and computational efficiency is
    paramount.

internalField():
internalFieldRef():
    Provides access to the DimensionedField<Type, GeoMesh> of values on
    the internal mesh-type for which the GeometricField is defined and
    supports dimension and checking and mesh-consistency checking.

applications/utilities/postProcessing/graphics/PV3Readers/PV3FoamReader/vtkPV3Foam/vtkPV3FoamPointFields.H

@@ -152,7 +152,7 @@ void Foam::vtkPV3Foam::convertPointFields
             // Extract the field on the zone
             Field<Type> fld
             (
-                ptf.internalField(),
+                ptf.primitiveField(),
                 mesh.faceZones()[zoneId]().meshPoints()
             );
 

applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamPointFields.H

@@ -152,7 +152,7 @@ void Foam::vtkPVFoam::convertPointFields
             // Extract the field on the zone
             Field<Type> fld
             (
-                ptf.internalField(),
+                ptf.primitiveField(),
                 mesh.faceZones()[zoneId]().meshPoints()
             );