ss: Add benchmarks for the threaded history tree

ss: Add benchmarks for the threaded history tree

This adds a new benchmark for the threaded history tree backend. It benchmarks
the insertion of intervals in the state system, single, full queries and
history range queries.

Change-Id: I4ac8eea4a6979c4f70b6d584b26ad3fc92ae4900
Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Reviewed-on: https://git.eclipse.org/r/66891
Reviewed-by: Hudson CI
Reviewed-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Tested-by: Alexandre Montplaisir <alexmonthy@efficios.com>