Merge remote-tracking branch 'origin/feature/8401_icat_update_query_lang'
Merge remote branch 'origin/feature/8382_cppcheck_warnings'
Re #8463. Remove unused DataPointMarker class.
Re #8463. Remove unused PlotEnrichement class.

It was a base to the ArrowMarker & ImageMarker classes, but was not doing
anything. The only place it was specifically mentioned, it was calling
a virtual method on an instance of one of those base classes that is
overridden in those classes.
Merge branch 'feature/8463_remove_unused_classes' into develop

Conflicts:
	Code/Mantid/MantidPlot/src/SelectionMoveResizer.cpp