Use `Name` component in warnings and errors regarding entities

I sometimes see warnings like

`.../bevy_hierarchy-0.15.1/src/hierarchy.rs:49:19: Could not despawn entity 1684v2#8589936276 because it doesn't exist in this World. See: https://bevyengine.org/learn/errors/b0003`

in my game. There are usually a lot of different entities in serious games. So it's quite hard to find the exact entity after(!) it is already despawned.

## What solution would you like?

Maybe we could add some kind of mapping from despawned entities to their original `Name` component while despawning (only in debug mode). This would **really** help identifying these entities while developing.

There should be a rule on when the entity gets removed from this mapping, to prevent memory problems. Maybe after some update cycles, or something like that.

## What alternative(s) have you considered?

Guessing what entity it could be, by observing the situation as soon as the log message occurs.