TrigMessageSvc: Implement asynchronous reporting
Implement asynchronous reporting during the event loop to avoid potential deadlocks (e.g. ATR-20664). This is modelled after Gaudi's InertMessageSvc using a separate thread for the message reporting. However, since we do not want to have a separate thread around before forking, we limit this feature to the event loop.
Edited by Frank Winklmeier