some headers are not self-contained, as they depend on symbols from headers which aren't included
- Enhance CMakeLists.txt files. - Move to Boost Test from Google Test to support pre-C++11 compilers. - Add more configurations on CI matrix builds. - Other minor fixes
Add support for the following types: - `std::array<std::byte>` - `std::span<char>` - `std::span<unsigned char>` - `std::span<std::byte>`
Tim Blechmann