segmentstore: fix incorrect iteration order in segment history

segmentstore: fix incorrect iteration order in segment history

The initial values for minEnd and maxStart times would lead to
incorrect orders during tree build.
Also, the bounds for the node are now serialized.
Add a test to ensure the order is right.

Change-Id: I0c0811f725fbdb3c06e45685f511fac060876b6d
Signed-off-by: Loïc Prieur-Drevon <loic.prieurdrevon@gmail.com>
Reviewed-on: https://git.eclipse.org/r/95945
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Reviewed-by: Hudson CI
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>