ActiveQt fails to handle VT_UNKNOWN

ActiveQt fails to handle VT_UNKNOWN the same way it does VT_DISPATCH, as a result, ActiveQt fails to recover wrapped IID_IAxServerBase objects.

This ActiveQt bug was exposed by another bug in pywin32:
https://github.com/mhammond/pywin32/issues/1934

When doing something like this in Python:
foo = server.getFoo()
server.doSomething(foo)

If "foo" is created by ActiveQt, then pywin32 passes the object as a VT_UNKNOWN, instead of a VT_DISPATCH, so ActiveQt fails to recover the object.

ActiveQt should do the same for both VT_DISPATCH and VT_UNKNOWN and attempt to Query Interface for IID_IAxServerBase in order to unwrap it and retrieve the correct object.