More "subject" values for Entity Filters.

Currently, the filter subjects include: block, self, other, target, damager, parent, and player. My suggestion is that several other important values be added to the subjects: [owner, owned, vehicle, passenger, child, sibling, spawner] This is because I have noticed a significant problem with the filters: it is difficult to use the appropriate subjects in cases involving hierarchies and mounts. If someone currently tries to assign an attribute of authority to a child or owned entity, they must use "minecraft:nearest_attackable_target" to designate this entity as a target and then use subject: target — which is inefficient and redundant, especially given the lack of a simpler alternative.