This deprecates the Event constructor and the ``ts`` parameter of Enqueue()
Instead, versions are introduced that take a detail::MetadataVectorPtr which
can hold the network timestamp metadata and is meant to be allocated by the
caller instead of automatically during Enqueue() or within the Event
constructor.
This also introduces a BifConst ``EventMetadata::add_network_timestamp`` to
opt-in adding network timestamps to events globally. It's disabled by
default as there are not a lot of known use cases that need this.
This adds compatibility tests for receiving non-timestamped events as
well as providing timestamps via broker websockets.
Co-authored-by: Arne Welzel <arne.welzel@corelight.com>
