Project submission: rav2d — memory-safe AV2 video decoder (Rust port of dav2d)

[stukenov]

Submitting a project that aligns with the memory safety initiative: rav2d — a complete Rust port of dav2d (AV2 video decoder). Follows the rav1d approach, extended to AV2. 47K+ lines of Rust, 786 tests. Repo: https://github.com/stukenov/rav2d