patch 9.1.1540: completion: menu state wrong on interruption

patch 9.1.1540: completion: menu state wrong on interruption

Problem:  completion: menu state wrong on interruption
          (Maxim Kim)
Solution: Call show_pum() if completion was interrupted
          (Girish Palya).

Popup menu was not built after fuzzy sorting, so internal state wasn't
reflected on screen.

No test. Couldn't get the terminal test to trigger both interruption and
refresh together.

fixes: #17725
closes: #17736

Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>