feat: implement machine key provider

- implement logic for hashing machine key
- extracted interfaces

src/StevanFreeborn.Extensions.Configuration.Secure/Cryptography/MachineIdKeyProvider.cs

@@ -1,5 +1,17 @@
+using System.Security.Cryptography;
+using System.Text;
+
 namespace StevanFreeborn.Extensions.Configuration.Secure.Cryptography;
 
-internal sealed class MachineIdKeyProvider
+internal sealed class MachineIdKeyProvider(IMachineIdKeyGenerator generator) : IEncryptionKeyProvider
 {
+  private readonly IMachineIdKeyGenerator _generator = generator;
+
+  public byte[] GetKey()
+  {
+    var machineId = _generator.GetId();
+    var @bytes = Encoding.UTF8.GetBytes(machineId);
+    using var sha256 = SHA256.Create();
+    return sha256.ComputeHash(@bytes);
+  }
 }