Need to specify the requirements [utility.arg.requirements] on types within GraphicsMath and GraphicsSurfaces #172
Description
e.g. GraphicsSurfaces::paths::abs_matrix_data_type should be EqualityComparable, CopyConstructible, CopyAssignable, Destructible, and probably Swappable (it gets that by being MoveConstructible and MoveAssignable but maybe we should ensure that implementers do not disable it).