Rollup merge of #135799 - aDotInTheVoid:skrrt-skrrt-revrrt, r=GuillaumeGomez

rustdoc-json: Rename `Path::name` to `path`, and give it the path again.

Closes: #135600.

Reverts #134880 (Effectively, but not actually, as the `FORMAT_VERSION` needs to be bumped, changed docs/tests). CC `@AS1100K.`

Also CC `@obi1kenobi` `@LukeMathWalker`

Still needs before being merge-ready:
- [x] Tests for cross-crate paths
- [x] (Maybe) Document what the field does.
- [x] Decide if the field rename is good (rust-lang/rust#135799 (comment))
- [ ] Squash commits.

r? `@GuillaumeGomez`

Author: matthiaskrgr