Added some todos for future tasks

Author: hiranya911

FirebaseAdmin/FirebaseAdmin/FirebaseException.cs

@@ -22,10 +22,10 @@ namespace FirebaseAdmin
     public sealed class FirebaseException : Exception
     {
         internal FirebaseException(string message)
-        : base(message) { }
+        : base(message) { } // TODO: Remove this constructor
 
         internal FirebaseException(string message, Exception inner)
-        : base(message, inner) { }
+        : base(message, inner) { } // TODO: Remove this constructor
 
         internal FirebaseException(ErrorCode code, string message, Exception inner = null)
         : base(message, inner)
@@ -36,6 +36,6 @@ internal FirebaseException(ErrorCode code, string message, Exception inner = nul
         /// <summary>
         /// Gets the platform-wide error code associated with this exception.
         /// </summary>
-        public ErrorCode ErrorCode { get; private set; }
+        internal ErrorCode ErrorCode { get; private set; } // TODO: Expose this as public
     }
 }