Draft: dvdread: test newer version that doesn't rely on structure packing

LLVM/Clang doesn't support the -mno-ms-bitfields and attribute packed. Current libdvread assumes the compiler (gcc or MSVC) supports it and reads structures straight from the disc. This result is some incorrect reading when using LLVM and even some crashes.

This MR attempts to provide a test environment of MR libdvdread!22 which reads data bits by bits (more like bytes). We need to test a lot of DVD to validate this fundamental change. I did a few pass reviewing my changes based on the original structure but there's always the possibility a bug has been introduced. There are a few parts of the code I never reached in my tests.

This includes:

• libdvdread!22
• libdvdread!31
• and the matching dvdnav libdvdnav!50