Require 2FA token in order to disiable 2FA. Added 2FA recovery code to data/domain model and exposed recover and regenerate 2FA APIs

src/Api/Models/Request/Accounts/RegenerateTwoFactorRequestModel.cs

@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Api.Models
+{
+    public class RegenerateTwoFactorRequestModel
+    {
+        [Required]
+        public string MasterPasswordHash { get; set; }
+        [Required]
+        [StringLength(50)]
+        public string Token { get; set; }
+    }
+}