Merge the dialog floating window callbacks and function calls into one.
Unique window ids across vcl::Window is enough to distinguish between
them.

Floating windows don't have a LOK notifier as they are created in the
vcl itself (so we can't access them from sfx2). Use the parent LOK
notifier in that case (which would be a dialog).

This API should also help in autopopup filter tunneling later.

Change-Id: I63a2c97ffdd84695dc967e14c793089a7c50b41b