For an svt_graph, returns the global warnings table. For an
svt_features, prepends the manifest issues. For an svt_inventory,
returns the union of every feature's inventory warnings tagged with
the owning feature name.
For an svt_graph, returns the global warnings table. For an
svt_features, prepends the manifest issues. For an svt_inventory,
returns the union of every feature's inventory warnings tagged with
the owning feature name.