`NameOrEntity` is difficult to `Query::get`

## What problem does this solve or what need does it fill?

Iterating a `Query` is pretty ergonomic: you just iterate through the query and it lets you display print the entity name. Quite nice! However if you need to use `Query::get` the situation is more complicated. If you `Query::::get`, you get back a `Result` since the entity may not exist - this is standard and expected, however handling this is a pain today.

For a concrete example, I have an observer that is triggered on `Pointer`. However another system can despawn this entity before the `Pointer` event is triggered. Trying to debug something, I added a `Query` and did `names.get(trigger.entity())`. `Result` doesn't implement `Display` though, so I unwrap the result - but since the entity is already despawned, the query doesn't find anything. Therefore, my app panics.

The "proper" way to handle this is with:

```rust
names.get(trigger.entity()).unwrap_or(NameOrEntityItem { name: None, entity: trigger.entity() })
```

## What solution would you like?

Ideally all this logic would be bundled into an associated function on `NameOrEntity`, for example `NameOrEntity::get_from_query(names, trigger.entity())`.

## What alternative(s) have you considered?

We could instead make an extension trait for `Query`, but this seems less discoverable and not that much more useful.