Model world borrow in Query more accurately

[BoxyUwU]

Objective

Query is an extremely error prone type to implement things on as the &'world World field lets safe code do lots of unsound things with.

Solution

newtype the &'world World and provide an API that more closely matches what the &'world World is representing (See module and type level docs on QueryWorldBorrows for more info)

---

This diff mostly ended up being doc comments and safety comments 😆

[alice-i-cecile]

I like this direction a lot; I found the lifetimes here incredibly confusing and error prone when working on PRs that modify Query.

[BoxyUwU]

for a reason why this PR is important see: #6214 which added a Debug impl to Query which passes an &World out to safe code which could very quickly turn into unsoundness if someone helpfully makes the Debug impl on world try to show you components. With this PR it requires a line of unsafe code which helpfully points out to me that we need to be careful about what gets accessed from the &World and I can very quickly see that we are not

[BoxyUwU]

(going to put this as a draft PR til I rewrite some doc comments)

[CGMossa]

Why was this closed?