sampledSurface::writers: Added writeFormat option to select ascii or binary

e.g. in tutorials/incompressible/pisoFoam/LES/motorBike/motorBike/system/cuttingPlane

    surfaceFormat   vtk;
    writeFormat     binary;
    fields          (p U);

selects writing the VTK surface files in binary format which significantly
speeds-up reading of the files in paraview.

Currently binary writing is supported in VTK and EnSight formats.

tutorials/multiphase/interFoam/RAS/DTCHullWave/system/controlDict

@@ -66,6 +66,7 @@ functions
         startTime       10;
 
         surfaceFormat   vtk;
+        writeFormat     binary;
         fields          (p_rgh U);
 
         interpolationScheme cellPoint;