sampledSet: Added cellSet and faceSet sampled sets

Added sets for sampling the cell-centres and face-centres of a cellSet
or faceSet. Example usage:

    sets
    (
        c0
        {
            type cellSet;
            set c0;
            axis xyz;
        }

        f0
        {
            type faceSet;
            set f0;
            axis xyz;
        }
    );

src/sampling/sampledSet/faceSetSampledSet/faceSetSampledSet.C

@@ -0,0 +1,88 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2020 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "faceSetSampledSet.H"
+#include "faceSet.H"
+#include "polyMesh.H"
+#include "addToRunTimeSelectionTable.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace sampledSets
+{
+    defineTypeNameAndDebug(faceSetSampledSet, 0);
+    addToRunTimeSelectionTable(sampledSet, faceSetSampledSet, word);
+}
+}
+
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+void Foam::sampledSets::faceSetSampledSet::genSamples()
+{
+    const labelList faces(faceSet(mesh(), setName_).toc());
+
+    setSamples
+    (
+        List<point>(IndirectList<point>(mesh().faceCentres(), faces)),
+        labelList(IndirectList<label>(mesh().faceOwner(), faces)),
+        faces,
+        labelList(faces.size(), 0),
+        scalarList(identity(faces.size()))
+    );
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::sampledSets::faceSetSampledSet::faceSetSampledSet
+(
+    const word& name,
+    const polyMesh& mesh,
+    const meshSearch& searchEngine,
+    const dictionary& dict
+)
+:
+    sampledSet(name, mesh, searchEngine, dict),
+    setName_(dict.lookup("set"))
+{
+    genSamples();
+
+    if (debug)
+    {
+        write(Info);
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::sampledSets::faceSetSampledSet::~faceSetSampledSet()
+{}
+
+
+// ************************************************************************* //