Inside lambda block the type argument completion is not working due to
the ParameterizedSingleTypeReference is not resolved. This fix will try
to move the ParameterizedSingleTypeReference expression as a lambda
block statement so that it get resolved when resolving the
CompilationUnit.

Also reverted and adjusted the
https://bugs.eclipse.org/bugs/show_bug.cgi?id=460410

Change-Id: Ib8bbe848675fc961eb69952039e4314ace9e25e2
Signed-off-by: Gayan Perera <gayanper@gmail.com>