* fix validation in new form layout
* pin mediatr to last oss version
* update dependencies
* cleanup code in core
* cleanup code in ffmpeg
* cleanup code in infra
* cleanup code in scanner
* cleanup code in application
* cleanup main code
* cleanup test code
* solution-wide code cleanup
* wip
* fix songs again
* don't use lists of video and audio input files
* test concat command output
* move concat pipeline
* start to use ffmpeg state
* add ffmpeg state and audio state
* audio state is required
* attach input options directly to input files
* move filters to input files
* add watermark support