Fix: src.ctf.lttng-live: missing ordering within traces and streams

Fix: src.ctf.lttng-live: missing ordering within traces and streams

Issue
=====
Sorting of messages with the same timestamps are different from the
messages sorted by the a `flt.utils.muxer` component. This is caused by
the fact that we are not sorting messages within sessions and traces
but only across the different session currently handled by the
component.

Indeed, we need to sort messages at across three locations in the code
to ensure proper ordering: sessions, traces, and streams.

Solution
========
Handle messages with the same timestamps at each of these three
locations using the `common_muxing_compare_messages()` function.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: Iadc66f3b6a12f34522f6364b3f47f15eefa87930
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1888
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Tested-by: jenkins <jenkins@lttng.org>