setAndNormalToFaceZone: Standardise input syntax

The set is now specified with a "set" keyword, as the fact that it is a
faceSet is clear from context. The old "faceSet" keyword is maintained
for backwards compatibility.

src/meshTools/sets/faceZoneSources/setAndNormalToFaceZone/setAndNormalToFaceZone.C

@@ -64,7 +64,7 @@ Foam::setAndNormalToFaceZone::setAndNormalToFaceZone
 )
 :
     topoSetSource(mesh),
-    setName_(dict.lookup("faceSet")),
+    setName_(dict.lookupBackwardsCompatible<word>({"set", "faceSet"})),
     normal_(dict.lookup("normal"))
 {}