Added MasterPasswordUnlock to UserDecryptionOptions as part of identity response (#6093)

src/Core/KeyManagement/Models/Response/MasterPasswordUnlockResponseModel.cs

@@ -0,0 +1,20 @@
+using System.ComponentModel.DataAnnotations;
+using Bit.Core.Enums;
+using Bit.Core.Utilities;
+
+namespace Bit.Core.KeyManagement.Models.Response;
+
+public class MasterPasswordUnlockResponseModel
+{
+    public required MasterPasswordUnlockKdfResponseModel Kdf { get; init; }
+    [EncryptedString] public required string MasterKeyEncryptedUserKey { get; init; }
+    [StringLength(256)] public required string Salt { get; init; }
+}
+
+public class MasterPasswordUnlockKdfResponseModel
+{
+    public required KdfType KdfType { get; init; }
+    public required int Iterations { get; init; }
+    public int? Memory { get; init; }
+    public int? Parallelism { get; init; }
+}