Use Identifier for Id

Author: carolynvs

src/corelib/Compute/v2_1/Volume.cs

@@ -14,7 +14,7 @@ public class Volume : VolumeDefinition, IServiceResource
         /// The volume identifier.
         /// </summary>
         [JsonProperty("id")]
-        public string Id { get; set; }
+        public Identifier Id { get; set; }
 
         /// <summary>
         /// 

src/corelib/Compute/v2_6/Server.cs

@@ -16,7 +16,7 @@ public class Server : IHaveExtraData
         /// <value>
         /// The identifier.
         /// </value>
-        public string Id { get; set; }
+        public Identifier Id { get; set; }
 
         /// <summary>
         /// The xtended data