lttng.control: Improve regular expression recognition for pre-MI LTTng

Changed the regular expression matcher that detects if a session has
exclusions and is using a filter.There was some weird behavior when
those two things were enabled at the same time.

Also updated some tests to make sure the functionality works properly.

Change-Id: I407b6ad9b701e593a963e67c52dcc90eb7f185a9
Signed-off-by: Bruno Roy <bruno.roy@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/76393
Reviewed-by: Hudson CI
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>