[HEAD MERGE] Implement the relayd live features

Create relayd session from the sessiond with additional parameters
Relayd listen on 1 additionnal port
Version exchange with the viewer
List the sessions with number of connected client (max 1 for now)
Attach to a session with seek parameter (begin or last for now)
List the streams of a session
Get the indexes per stream
Get data packets
Flag metadata streams
Match ctf_traces based on the trace path
Handle the synchronisation of the metadata (prevent the viewer from
reading a packet if it does not have the complete metadata)
Send the metadata
Ioctl to get the current timestamp
Inactive stream beacon

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>