ENH: consolidate processorTopology handling for volume and area meshes

- relocate templating to factory method 'New'.
  Adds provisions for more general re-use.

- expose processor topology in globalMesh as topology()

- wrap proc->patch lookup as processorTopology::procPatchLookup method
  (failsafe). May consider using Map<label> for its storage in the
  future.

applications/test/processorTopology/Test-processorTopology.C

@@ -44,7 +44,7 @@ int main(int argc, char *argv[])
     argList::noFunctionObjects();
     argList::addNote
     (
-        "Create a metis graph file representation for an OpenFOAM mesh"
+        "Create graph of OpenFOAM mesh connections"
     );
 
     #include "setRootCase.H"
@@ -59,9 +59,9 @@ int main(int argc, char *argv[])
     #include "createTime.H"
     #include "createPolyMesh.H"
 
-    const globalMeshData& globData = mesh.globalData();
-
-    const labelListList& connectivity = globData;
+    // Adjacency table
+    const labelListList& connectivity =
+        mesh.globalData().topology().procNeighbours();
 
     if (Pstream::master())
     {

applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C

@@ -60,6 +60,7 @@ Description
 #include "wedgePolyPatch.H"
 #include "planeExtrusion.H"
 #include "emptyPolyPatch.H"
+#include "processorPolyPatch.H"
 #include "processorMeshes.H"
 #include "hexRef8Data.H"
 

applications/utilities/mesh/manipulation/createBaffles/createBaffles.C

@@ -57,6 +57,7 @@ Description
 
 #include "fvMeshTools.H"
 #include "topoSet.H"
+#include "processorPolyPatch.H"
 #include "processorMeshes.H"
 
 using namespace Foam;