lttng: Add an in-depth test for full state system queries

lttng: Add an in-depth test for full state system queries

Also add a small program/script in the 'headless' package to
regenerate those reference values easily, in case we need to
update the test values after we modify the kernel state provider.

Change-Id: I5cf66367a246ca78bb85f4cb3b3ad3c24ea6142e
Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-on: https://git.eclipse.org/r/10908
Tested-by: Hudson CI
Reviewed-by: Bernd Hufmann <bhufmann@gmail.com>
IP-Clean: Bernd Hufmann <bhufmann@gmail.com>