fix ffmpeg download button behavior

1.2.2.0

fix download button behavior

update to net6

• update to net6
• update nuget packages
• add download button for ffmpeg
• methods use readonlymemory

Update nuget packages

1.1.1.0

Merge branch 'master' of https://github.com/kaanlab/FFUITools

Merge to CliWrap for ffmpeg

1.1.0.0

Merge to CliWrap for ffmpeg

Add MultiThread support

v.1.0.1.0

Add MultiThread support