ENH: make sourceInfo sub-dictionary optional for topoSet (#1060)

- helps reduce clutter in the topoSetDict files.

  Caveats when using this.

  The older specification styles using "name" will conflict with the
  set name. Eg,

    {
        name    f0
        type    faceSet;
        action  add;
        source  patchToFace;
        sourceInfo
        {
            name   inlet;
        }
    }

    would flattened to the following
    {
        name    f0
        type    faceSet;
        action  add;
        source  patchToFace;
        name   inlet;
    }
    which overwrites the "name" used for the faceSet.

    The solution is to use the updated syntax:

    {
        name    f0
        type    faceSet;
        action  add;
        source  patchToFace;
        patch   inlet;
    }

tutorials/mesh/refineMesh/refineFieldDirs/system/topoSetDict.range2

@@ -21,13 +21,10 @@ actions
         name    range1;
         type    cellSet;
         action  new;
-        source fieldToCell;
-        sourceInfo
-        {
-          field       radiusFieldXY;
-          min         7.00;
-          max         18.47;
-        }
+        source  fieldToCell;
+        field   radiusFieldXY;
+        min     7.0;
+        max     18.47;
     }
 );