userWaiting function
Handles the event when a user joins the waiting room.
This function displays a notification if showAlert is provided and increments
the waiting room request count by calling updateTotalReqWait.
Example usage:
userWaiting(UserWaitingOptions(
  name: "John Doe",
  showAlert: (message, type, duration) => print("Alert: $message"),
  totalReqWait: 3,
  updateTotalReqWait: (total) => print("Updated total: $total"),
));
Implementation
void userWaiting(UserWaitingOptions options) {
  try {
    // Display alert if provided
    options.showAlert?.call(
      message: '${options.name} joined the waiting room.',
      type: 'success',
      duration: 3000,
    );
    // Increment the total waiting requests and update
    final updatedTotalReqWait = options.totalReqWait + 1;
    options.updateTotalReqWait(updatedTotalReqWait);
  } catch (error) {
    if (kDebugMode) {
      print("Error in userWaiting: $error");
    }
  }
}