madVR: Hook DXVA decoder to have status and logging.
Cosmetics: Use the IID_PPV_ARGS macro when possible (1/2).
Cosmetics: Use the IID_PPV_ARGS macro when possible (2/2).
Improve the reliability of the [DXVA] indicator in the status bar.

Sometimes the indicator wasn't shown while hardware acceleration was used.

This commit fixes #3518.
Get the DXVA status once and for all when opening the file.

No need to check it every time the status bar is updated.
Cosmetics: Consistently name the video renderer data variable.
Renderer statistics: Show the DXVA info from LAV when available.