linux.swtbot: Add basic critical flow view test.

linux.swtbot: Add basic critical flow view test.

This tests runs a true integration test with the control flow view.
It signals the critical path view from a right click on the cfv.

Change-Id: Icc04e03de0b745eb966bb711494eab749b8b08c6
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/72360
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>