Add IncludePassword parameter to Get Connection String request (#670)

* Add IncludePassword flag to get connection string method

* Override connection application name

* Fix typo

* Fix test break

* Use ****** as password placeholder

src/Microsoft.SqlTools.ServiceLayer/Connection/Contracts/GetConnectionStringParams.cs

@@ -14,5 +14,10 @@ namespace Microsoft.SqlTools.ServiceLayer.Connection.Contracts
         /// URI of the owner of the connection
         /// </summary>
         public string OwnerUri { get; set; }
+
+        /// <summary>
+        /// Indicates whether the password should be return in the connection string
+        /// </summary>
+        public bool IncludePassword { get; set; }
     }
 }