[PATCH] user32/combo: Set listview popup height correctly and add tests

[Fabian Maurer]

> 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=32672

> === w7u (32 bit combo) ===
> combo.c:786: Test failed: Test 2, expected list height to be 16, got 0
> combo.c:786: Test failed: Test 3, expected list height to be 16, got 18
> combo.c:786: Test failed: Test 4, expected list height to be 32, got 18
> combo.c:786: Test failed: Test 5, expected list height to be 32, got 36
> combo.c:786: Test failed: Test 6, expected list height to be 32, got 36
> combo.c:786: Test failed: Test 7, expected list height to be 32, got 36
> combo.c:786: Test failed: Test 8, expected list height to be 32, got 36
> combo.c:786: Test failed: Test 11, expected list height to be 16, got 0
> combo.c:786: Test failed: Test 12, expected list height to be 16, got 18
> combo.c:786: Test failed: Test 13, expected list height to be 32, got 18
> combo.c:786: Test failed: Test 14, expected list height to be 48, got 36
> combo.c:781: Test failed: Test 15, expected list height to be 48, got 54
> combo.c:786: Test failed: Test 16, expected list height to be 64, got 54
> combo.c:786: Test failed: Test 17, expected list height to be 64, got 72
> combo.c:315: Test failed: Focus not on Main Window, instead on 00000000

Fixed the one failure, but it looks like this machine does have a different 
listview-item size. Have to look into it.