[Feature Request] Support default AV1 output option, take 2

[saschanaz]

Is your feature request related to a problem? Please describe.
It has been a few years since I opened #547. It seems it's now supported well.

Describe the solution you'd like

-vsync passthrough 
-hwaccel auto 
{I} 
-c:v librav1e 
-preset fast 
-pix_fmt yuv420p 
-vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" 
-crf 30 
-b:v 0 
-f webm 
{O}

Describe alternatives you've considered
libaom-av1 also exists but librav1e was over 2 times faster and generated smaller file with the above options.

Additional context

[NickeManarin]

I'll add support for 3 new encoders (libaom (libaom-av1), SVT-AV1 (libsvtav1), and rav1e (librav1e)), but the correct version of ffmpeg.exe needs to be used.

I'll update the ffmpeg downloader to get version 4.4.1.