message: Signals fix in test-service-load: send signals only when the client is not disconnected or disposed
  in loadTestDataStore.ts, send signals only when runtime is not
  disconnected or disposed
  this should hopefully reduce the recent uptick in
  `submitSignalDisconnected` errors we have been seeing
diff: @@ -513,11 +513,13 @@ class LoadTestDataStore extends DataObject implements ILoadTest {
  const signalsGapMs = cycleMs / signalsPerCycle;
  let submittedSignals = 0;
  try {
  - while (submittedSignals < clientSignalsSendCount) {
  + while (submittedSignals < clientSignalsSendCount && !this.runtime.disposed) {
  // all the clients are sending signals;
  // with signals, there is no particular need to have staggered writers and readers
  + if (this.runtime.connected) {
  this.runtime.submitSignal("generic-signal", true);
  submittedSignals++;
  + }
  // Random jitter of +- 50% of signalGapMs
  await delay(signalsGapMs + signalsGapMs * random.real(0, .5, true)(config.randEng));
  }
  