ENH: place more patch field attributes under template invariant Base

- attributes such as assignable(), coupled() etc

- common patchField types: calculatedType(), zeroGradientType() etc.
  This simplifies reference to these types without actually needing a
  typed patchField version.

ENH: add some basic patchField types to fieldTypes namespace

- allows more general use of the names

ENH: set extrapolated/calculated from patchInternalField directly

- avoids intermediate tmp

applications/test/pointField/Test-PointField.C

@@ -53,13 +53,13 @@ int main(int argc, char *argv[])
         (
             "U",
             runTime.timeName(),
-            mesh,
+            pMesh.thisDb(),
             IOobject::NO_READ,
-            IOobject::AUTO_WRITE
+            IOobject::NO_WRITE
         ),
         pMesh,
-        dimensionedVector(dimLength, Zero),
-        pointPatchVectorField::calculatedType()
+        dimensionedVector(dimLength, Zero)
+        // pointPatchFieldBase::calculatedType()
     );
 
     pointVectorField V(U + 2*U);