ENH: improve consistency of ListOps and stringListOps

- subsetList, inplaceSubsetList with optional inverted logic.

- use moveable elements where possible.

- allow optional starting offset for the identity global function.
  Eg,  'identity(10, start)' vs 'identity(10) + start'

src/meshTools/indexedOctree/treeDataFace.C

@@ -122,8 +122,7 @@ Foam::treeDataFace::treeDataFace
     mesh_(patch.boundaryMesh().mesh()),
     faceLabels_
     (
-        identity(patch.size())
-      + patch.start()
+        identity(patch.size(), patch.start())
     ),
     isTreeFace_(mesh_.nFaces(), 0),
     cacheBb_(cacheBb)