Refactor code structure for improved readability and maintainability

src/__Libraries/StellaOps.Cryptography.Kms/Pkcs11KmsClient.cs

@@ -1,6 +1,7 @@
 using System.Collections.Concurrent;
 using System.Collections.Immutable;
 using System.Security.Cryptography;
+using Microsoft.IdentityModel.Tokens;
 
 namespace StellaOps.Cryptography.Kms;