Python: allow CaptureArgumentNodes as multiple arguemnts

These are the labmda self references. This is similar to
how `BlockParameterArgumentNode` is excluded for Ruby.

It is important that we restrict `call` in this logic.
Otherwise, we get a cartesian product and the consistency
check runs for a very long time...

Author: yoff

python/ql/consistency-queries/DataFlowConsistency.ql

@@ -140,6 +140,9 @@ private module Input implements InputSig<PythonDataFlow> {
       arg = other.getArgument(any(ArgumentPosition p | p.isSelf())) and
       other.getNode().getScope() = f
     )
+    or
+    arg = call.getArgument(_) and
+    arg instanceof CaptureArgumentNode
   }
 }