[Roadmap] Turn `cargo dev` into Clippys `./x.py`

[flip1995]

There's already cargo dev which makes Clippy development easier and more
pleasant. This can still be expanded, so that it covers more areas of the
development process.

Steps to completion:

• bless execute UI-tests and update reference files
• init include setup-toolchain.sh in clippy_dev (outdated)
• pr (?) Run everything (fmt, update_lints, ...?), so that the changes probably pass CI
• deprecate to deprecate a Clippy lint. This is especially useful if people want to uplift Clippy lints.
• Better integrate cargo dev in rust-lang/rust so that commands are also usable there
• Add git commit hooks running cargo dev commands before committing (Added cargo dev setup git-hook and updated cargo dev setup intellij including a remove command #7361)
• cargo dev rename_lint(See issue cargo dev rename_lint #7799)
• cargo dev dogfood --fix
• ... ideas?

These are some ideas, that I had, maybe we can even further expand the clippy_dev tool.