message: Add error event when we are not caught up with summarizing
  AB#160
  * Add telemetry event
  * Fix merge conflicts
  * Use property shorthand
diff: @@ -339,6 +339,10 @@ export class RunningSummarizer implements IDisposable {
  // lockedSummaryAction() will retry heuristic-based summary at the end of current attempt
  // if it's still needed
  this.tryWhileSummarizing = true;
  + this.logger.sendErrorEvent({
  + eventName: "SummarizingNotCaughtUp",
  + reason,
  + });
  return;
  }
  