ENH: consolidate 'formatOptions' handling for coordSetWriter/surfaceWriter

- replaced ad hoc handling of formatOptions with coordSetWriter and
  surfaceWriter helpers.

  Accompanying this change, it is now possible to specify "default"
  settings to be inherited, format-specific settings and have a
  similar layering with surface-specific overrides.

- snappyHexMesh now conforms to setFormats

  Eg,

      formatOptions
      {
          default
          {
              verbose     true;
              format      binary;
          }
          vtk
          {
              precision   10;
          }
     }

     surfaces
     {
         surf1
         {
             ...

             formatOptions
             {
                 ensight
                 {
                     scale   1000;
                 }
             }
         }
     }

tutorials/compressible/rhoPorousSimpleFoam/angledDuct/implicit/system/sampling

@@ -96,6 +96,14 @@ plane
 
     surfaceFormat   vtk;
 
+    formatOptions
+    {
+        default
+        {
+            verbose true;
+        }
+    }
+
     surfaces
     {
         zNormal

tutorials/compressible/rhoSimpleFoam/squareBend/system/sampling

@@ -44,6 +44,15 @@ __surfaceFieldValue
 
     writeFields     false;
     surfaceFormat   vtk;
+
+    formatOptions
+    {
+        default
+        {
+            verbose true;
+        }
+    }
+
     // writeArea       true;
 
     // resetOnStartUp  true;

tutorials/incompressible/simpleFoam/squareBend/system/sampling

@@ -44,6 +44,15 @@ __surfaceFieldValue
 
     writeFields     false;
     surfaceFormat   vtk;
+
+    formatOptions
+    {
+        default
+        {
+            verbose true;
+        }
+    }
+
     // writeArea       true;
 
     // resetOnStartUp  true;