Improve error message handling (#497)

- Add special handling for token expired errors so they send with a clear flag that'll allow clients to take action on this case
- Send error message instead of callstack for all messages, and ensure all resource manager paths send back inner exceptions so users can understand the true root cause.

src/Microsoft.SqlTools.ResourceProvider.Core/Common/ExpiredTokenException.cs

@@ -0,0 +1,53 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.Serialization;
+
+namespace Microsoft.SqlTools.ResourceProvider.Core
+{
+    /// <summary>
+    /// The exception is used if any operation fails as a request failed due to an expired token 
+    /// </summary>
+    public class ExpiredTokenException : ServiceExceptionBase
+    {
+        /// <summary>
+        /// Initializes a new instance of the ServiceFailedException class.
+        /// </summary>
+        public ExpiredTokenException()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the ServiceFailedException class with a specified error message.
+        /// </summary>
+        /// <param name="message">The error message that explains the reason for the exception. </param>
+        public ExpiredTokenException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the ServiceFailedException class with a specified error message 
+        /// and a reference to the inner exception that is the cause of this exception.
+        /// </summary>
+        /// <param name="message">The error message that explains the reason for the exception. </param>
+        /// <param name="innerException">The exception that is the cause of the current exception, or a null reference 
+        /// (Nothing in Visual Basic) if no inner exception is specified</param>
+        public ExpiredTokenException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the ServiceFailedException class with serialized data.
+        /// </summary>
+        /// <param name="info">The SerializationInfo that holds the serialized object data about the exception being thrown.</param>
+        /// <param name="context">The StreamingContext that contains contextual information about the source or destination.</param>
+        public ExpiredTokenException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+    }
+}