Add comment for explaining token cancellation (#387)

Author: AmeyaRele

src/TriggerBinding/SqlTableChangeMonitor.cs

@@ -156,6 +156,7 @@ public SqlTableChangeMonitor(
 
         public void Dispose()
         {
+            // When the CheckForChanges loop is finished, it will cancel the lease renewal loop.
             this._cancellationTokenSourceCheckForChanges.Cancel();
         }
 

src/TriggerBinding/SqlTriggerListener.cs

@@ -115,7 +115,6 @@ public async Task StartAsync(CancellationToken cancellationToken)
 
                     this._logger.LogInformation($"Starting SQL trigger listener for table: '{this._userTable.FullName}', function ID: '{this._userFunctionId}'.");
 
-                    // TODO: Check if passing the cancellation token would be beneficial.
                     this._changeMonitor = new SqlTableChangeMonitor<T>(
                         this._connectionString,
                         userTableId,