STYLE: qualify Swap with Foam:: prefix (visibility)

- drop unnecessary Foam::Swap specializations when MoveConstructible
  and MoveAssignable already apply. The explicit redirect to swap
  member functions was needed before proper move semantics where
  added.

  Removed specializations: autoPtr, refPtr, tmp, UList.
  Retained specialization: DynamicList, FixedList.

     Special handling for DynamicList is only to accommodate dissimilar
     sizing template parameters (which probably doesn't occur in
     practice).
     Special handling for FixedList to apply element-wise swapping.

- use std::swap for primitives. No need to mask with Foam::Swap wrapper

applications/test/FixedList2/Test-FixedList2.C

@@ -68,7 +68,7 @@ void runSwapTest
 
     for (label iLoop = 0; iLoop < nLoops; ++iLoop)
     {
-        Swap(list1, list2);
+        Foam::Swap(list1, list2);
     }
 
     Info<< "output 1: " << list1.first() << nl;