This commit introduces GRPC API for streaming sessions.
It adds structured events and sync streaming
that avoids storing events on disk.
You can find design in rfd/0002-streaming.md RFD.
Validate all incoming events (and archives) to ensure that the server ID
within the event matches the x509 identity of the connected host. This
check makes sure nodes can only submit events for themselves.
In addition, make sure session recordings to disk or S3 can not be
overwritten.
Jakub Nyckowski