Use vector of arrays instead of vector

Use the same structure as for the BP SEI

Includes:
- fix syntax element names for tracing
- add validation checks
- move validation check to correct place
- define `enum HrdType` for indexing by `NAL` or `VCL`
- consistently use `bp` variable name for BP SEI objects
- use `static_vector` instead of having separate variable for array size

Resolves compilation issue where unused variables triggered a warning

Updates CMake files to account for arm64 architecture.
Consider __ARM_NEON to detect ARM architecture in C++ code.