Allow 'Save' of Group Monitor telegrams whilst Group Monitor is running

Allow the users to 'save' or 'export' group monitor telegrams to a file whilst the capture is in progress.

Currently, the user has to stop monitoring, save to a file, then start monitoring again, during which time a critical event may have been missed in the monitor.

Allow the user to be able to save or export whilst a capture is in progress and simply include all telegrams that happen to be in the monitor at that point in time. Then there is no scope for telegrams to be missed.