acquireLock method
Acquire a lock for a component
Implementation
Future<SignalLock> acquireLock(String component) async {
  final lockId = await messageId();
  final lock = SignalLock(
    id: lockId,
    component: component,
    timestamp: DateTime.now(),
  );
  _locks[lockId] = lock;
  _clearAutoDisconnect();
  return lock;
}