This PR has no new code, it just moves a bunch of commonly used functions into a utility module instead of spreading them over various other modules and splits up the OpenSSL backend into several modules, matching the module structure of the RustCrypto backend.
coverage: 85.156%. remained the same
when pulling 3a8d205efe0dec71bfbca5e6706fef934e3496f7 on refactor_cose_utils_and_openssl
into c7f1691492779e3280a1d8b3ba575f60e796b8d9 on main.
This PR has no new code, it just moves a bunch of commonly used functions into a utility module instead of spreading them over various other modules and splits up the OpenSSL backend into several modules, matching the module structure of the RustCrypto backend.