[v6 5/6] user32: Send WM_NCPAINT and WM_ERASEBKGND when window is shown and add tests

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://testbot.winehq.org/JobDetails.pl?Key=28472

Your paranoid android.


=== w7u (32 bit msg) ===
msg.c:11986: Test failed: WmMouseHoverSeq: 0: the msg sequence is not complete: expected 0118 - actual 0000
msg.c:11988: Test failed: wrong tme.dwFlags 00000001, expected 00000000
msg.c:11988: Test failed: wrong tme.hwndTrack 0023014C, expected 00000000
msg.c:11988: Test failed: wrong tme.dwHoverTime 400, expected 0