trace: create CTF TDSL metadata in memory

trace: create CTF TDSL metadata in memory

Common trace format(CTF) defines the metadata[1][2] for trace events,
This patch creates the metadata for the DPDK events in memory and
later this will be saved to trace directory on rte_trace_save()
invocation.

[1] https://diamon.org/ctf/#specification
[2] https://diamon.org/ctf/#examples

Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: David Marchand <david.marchand@redhat.com>