When VIS_INHERIT_ID is in play, all mouse actions are processed on the parent.

It would be extremely useful to know which vis-child the mouse action came from. The information should be the ref string of the object that was interacted with. This would typically be the same as over-object, but in cases where VIS_INHERIT_ID is in play, it would differ. This would streamline the creation of complex multi-item HUD elements.

This would be useful for things like shared global click "hitboxes" that could be attached as a single group to a parent icon, or dynamic UI widgets.

To make this more useful for hierarchies of objects, a new vis_flag should be added in support of this: VIS_PASS_ID. Objects with VIS_PASS_ID set will pass their own id to the inheriting object. The last object downward in the hierarchy to have VIS_PASS_ID set is the one that passes its id to the inheriting object's mouse parameter.