Cryptography: Added built-in support for Ed25519 algorithm.
Cryptography: Added Rebex.Security.Cryptography.AesGcm class (equivalent to .NET 5.0's AesGcm class, but available on all platforms including Microsoft .NET Framework 3.5).
Cryptography: Added SetOtherNames/GetOtherNames methods to CertificateInfo class ('Other Name' support in SANs).
Cryptography: AsymmetricKeyAlgorithm.ImportKey method can initialize Ed25519 key from seed (in addition to private key).
Cryptography: AsymmetricKeyAlgorithm.Register method made thread-safe.