TUT: add new tutorial case for turbulent inflow BCs

The following three synthetic turbulence inflow boundary conditions are
examined through single-cell-domain smooth-wall plane channel flow setup:

- turbulentDFSEMInlet
- turbulentDigitalFilterInlet variant=digitalFilter
- turbulentDigitalFilterInlet variant=reducedDigitalFilter

The examinations are performed in terms of the first-/second-order turbulence
statistics provided by (Moser et al., (1999)) doi.org/10.1063/1.869966
from smooth-wall plane channel flow direct numerical simulations at Re=395.

Serial executing:

./Allrun

Parallel (decompositionMethod=scotch) executing:

./Allrunparallel

tutorials/verificationAndValidation/turbulentInflow/system/decomposeParDict

@@ -0,0 +1,22 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  v1906                                 |
+|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    note        "mesh decomposition control dictionary";
+    object      decomposeParDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+numberOfSubdomains  6;
+
+method         scotch;
+
+// ************************************************************************* //