Ability to cancel entities looking at other entities

Is your feature request related to a problem?

When creating systems such as vanish or minigames where you want to hide spectators from other players, you are as it is right now faced with the issue that entities that look at players still will look at players that are vanished or spectating.
Right now there are only methods to make entities look at other entities, not an event or such that lets you cancel the act.

Describe the solution you'd like.

Essentially I want a way to toggle or cancel what entities look at what players (or other entities). This could for example be done through an event:

It would be a "EntityLookAtEntityEvent" or something along those lines, that lets you access the entity that tries to look, and the entity that it tries to look at, and then have it be cancellable.

Describe alternatives you've considered.

I've considered putting the players in spectator-mode, causing the entities to not look at players, but it would be very neat if something like this could be implemented.

Other

No response

The issue names no files, tests, or entry points. First review the existing entity look-at API and event patterns, then determine the appropriate cancellable event contract for the looking and target entities; done means the behavior can be prevented selectively without relying on spectator mode.