STYLE: use 'is_sorted()' instead of 'sorted()' for readers, Pair, ...

- avoids naming ambiguity between querying sorted state vs returning a
  sorted list (for example)

ENH: add 'good()' method to a few more classes

applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshIO.C

@@ -78,7 +78,7 @@ void Foam::conformalVoronoiMesh::timeCheck
 
         memInfo m;
 
-        if (m.valid())
+        if (m.good())
         {
             PrintTable<word, label> memoryTable
             (