public and private keys added to db and user domain. added account APIs got getting and putting keys.

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

@@ -0,0 +1,23 @@
+using Bit.Core.Domains;
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Api.Models
+{
+    public class KeysRequestModel
+    {
+        public string PublicKey { get; set; }
+        [Required]
+        public string PrivateKey { get; set; }
+
+        public User ToUser(User existingUser)
+        {
+            if(!string.IsNullOrWhiteSpace(PublicKey))
+            {
+                existingUser.PublicKey = PublicKey;
+            }
+
+            existingUser.PrivateKey = PrivateKey;
+            return existingUser;
+        }
+    }
+}