To support VA-API plugins we need to implement video frame copy as well,
as the plugins simply ignore downstream buffer alignment requirements.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45988
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=47084
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=49715
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52183Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>