Add basic flt.lttng-utils.debug-info tests

Add basic flt.lttng-utils.debug-info tests

This new test uses the bt2 Python bindings to test the
flt.lttng-utils.debug-info component class. The test opens the
tests/debug-info-data/trace trace and makes it pass through a
flt.lttng-utils.debug-info component to inject debugging information.
The test then checks that specific debugging information fields in
specific event notifications have the expected values.

This patch also removes the old tests/cli/test_debug_info.in test which
is not even enabled and relied on the output of sink.text.pretty.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>