GeometricField::internalField() -> GeometricField::internalFieldRef()

Non-const access to the internal field now obtained from a specifically
named access function consistent with the new names for non-canst access
to the boundary field boundaryFieldRef() and dimensioned internal field
dimensionedInternalFieldRef().

See also commit a4e2afa4b3

applications/test/mappedPatch/Test-MappedPatch.C

@@ -86,7 +86,7 @@ int main(int argc, char *argv[])
         patchFieldTypes
     );
 
-    cc.internalField() = mesh.C().internalField();
+    cc.internalFieldRef() = mesh.C().internalField();
     cc.boundaryFieldRef().updateCoeffs();
 
     forAll(cc.boundaryField(), patchi)