Grouping of events

When a single run produces multiple warnings, they all appear as independent events for the user or the sysadmin... This is not very convenient as this fills the logs and prevents seeing what is relevant. So grouping all events related to the same run together (at least in the events tables) might be something to consider.

The only issue could be if something else refers to a particular event (as it is currently understood) and it is therefore necessary to be able to find this exact event in the table.