Feat: add av1 support for smaller snapshots and videos

[BenediktBertsch]

Found out that the lib didnt support the AV1 format therefore I added it for myself.

With this you can create smaller images like this:

var source = FFProbe.Analyse(file.FullName);
var streamIndex = source.PrimaryVideoStream?.Index
                ?? source.VideoStreams.FirstOrDefault()?.Index
                ?? 0;
var args = FFMpegArguments
            .FromFileInput(file.FullName, false, options => options
            .Seek(TimeSpan.FromSeconds(source.Duration.TotalSeconds / 3)));
var opts = new Action<FFMpegArgumentOptions>(options => options.SelectStream((int)streamIndex, 0)
                                            .WithVideoCodec(VideoCodec.LibaomAv1)
                                            .WithFrameOutputCount(1)
                                            .Resize(null));
args.OutputToFile(name, false, opts).ProcessSynchronously();

This takes way longer but the size difference is huge for example: 1811KB in .png to 98KB in .avif

If there is anything missing to do like writing tests etc. just mention it. I havent seen any tests for the VideoCodec.Png therefore I didnt implement any tests yet.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 71.00%. Comparing base (f8407bc) to head (e8ef580).
Report is 25 commits behind head on main.

Files with missing lines	Patch %	Lines
FFMpegCore/FFMpeg/Enums/Enums.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #523      +/-   ##
==========================================
- Coverage   74.31%   71.00%   -3.31%     
==========================================
  Files         113      115       +2     
  Lines        2854     2925      +71     
  Branches        0      277     +277     
==========================================
- Hits         2121     2077      -44     
- Misses        733      740       +7     
- Partials        0      108     +108     

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