Multithreading chafa

[Notenlish]

On my VM it gives roughly a 3x speed improvement for caching
Using a threadpoolexecutor, for each frame a thread is used (for chafa and some simple data processing).
ffmpeg is still singlethreaded
ffmpeg is set to extract jpg instead of png now.
a new argument called --quality was added
its between 2(high quality) and 10(low quality)
this should provide significant performance improvement at no visible ascii output loss.

[Notenlish]

To further increase performance we can pipe the frames directly to chafa but trying to do it multithreaded would be a bit complicated

could try doing single threaded ffmpeg -> pipe image to chafa --> write frame to folder
could even add a --stream mode where anifetch doesnt wait for all the files to be cached and simply shows the frames as they appear. that would be cool.

[Notenlish]

It seems to me that when centered this PR crops the first and last rows of the chafa output.

These are from this PR:

these are from main:

[Notenlish]

fixed it, the issue was with the HEIGHT variable not being updated in main thread