Add GPAC with MP4Box and Bento4 binaries as a separate WASM file

Hello, as the title said, this is a suggestion if you could add and guide us through how to compile all of the following binaries. It would be really useful to add these binaries in order to work with media files as the pre-included FFmpeg doesn't have uncommon utilities that GPAC & MP4Box do and could achieve.

I've checked and linked the license for you if that could be included on a-Shell directly, it would seem they both use the GPL license which is a big no for the App Store submission. So you probably would have to compile into WASM binary for that.

Thank you for making a-Shell the best local Unix portable Terminal possible on iOS.

## GPAC (MP4Box)
Source: https://github.com/gpac/gpac
Licensing: https://gpac.io/licensing/

## Bento4
Source: https://github.com/axiomatic-systems/Bento4
Licensing: https://www.bento4.com/about/