ss: Change getIteratorOverQuark to a public class

ss: Change getIteratorOverQuark to a public class

This patch allows iteration to go backwards and forwards,
introduces a unit test and uses the new iterator for:
KernelThreadInformationProvider.getExecutableName

Change-Id: I41f35e30bd1984662f55b8809e2497a6c19d5468
Signed-off-by: Loïc Prieur-Drevon <loic.prieurdrevon@gmail.com>
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/85798
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Reviewed-by: Hudson CI