Media engine corresponding sources

Original upstream archives including license notices and build scripts. Licenses and build information.

Complete source manifest with upstream refs, byte sizes and SHA-256 checksums. Archives larger than 8 MiB are split: concatenate their numbered pieces in ascending order, then extract with tar -xzf.

The ffmpeg.wasm archive contains the Dockerfile, Makefile, build scripts, MIT wrapper sources and binding sources. Source archives retain their original component licenses.