Make checkAndCollapseGraph() public for testing
Test case for checkAndCollapseGraph()
Reverse assertions to be inline with testNG
Expand test case to cover ObjectiveSettings
Expand test case to cover LightSettings
Expand test case to cover DetectorSettings
Add getUniqueLightPath() method to optimise performance

This new method will reduce the number of LightPath objects
and by extension LogicalChannel objects when importing large
plates with these metadata populated.