There are cases in Windows10+ where the WM_PASTE message doesn't paste
the content of the clipboard.

This appeared in testing:
- almost always just after (for a couple of milliseconds) setting new
  content into the clipboard and closing it.
- in some unrelated rare occasions (like once for 400 runs).

It looks like another (installed) process had opened the clipboard and
forbids the paste command.
As WM_PASTE doesn't return success/error status, workaround it by
wrapping the WM_PASTE command into a helper, and retry when the
clipboard's content hasn't been pasted.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53276Signed-off-by: Eric Pouech <eric.pouech@gmail.com>