Cleanup gui plugin doxygen page

etc/doxygen/pages/GuiPlugins.dox

...ins/ArMemMemoryViewer/ArMemMemoryViewerWidgetController.h

source/RobotAPI/gui-plugins/ArViz/ArVizWidgetController.h

...xToGraspCandidates/BoxToGraspCandidatesWidgetController.h

...ins/DebugDrawerViewer/DebugDrawerViewerWidgetController.h

...plugins/GuiHealthClient/GuiHealthClientWidgetController.h

...xCalculator/HomogeneousMatrixCalculatorWidgetController.h

...s/LaserScannerPlugin/LaserScannerPluginWidgetController.h

...tPlugin/RobotUnitPlugin/RobotUnitPluginWidgetController.h