Always use the Rust version in package names

The format of the tarballs produced by CI is roughly the following:

    {component}-{release}-{target}.{ext}

While on the beta and nightly channels `{release}` is just the channel name, on the stable channel is either the Rust version or the version of the component we're shipping:

    cargo-0.47.0-x86_64-unknown-linux-gnu.tar.xz
    clippy-0.0.212-x86_64-unknown-linux-gnu.tar.xz
    llvm-tools-1.46.0-x86_64-unknown-linux-gnu.tar.xz
    miri-0.1.0-x86_64-unknown-linux-gnu.tar.xz
    rls-1.41.0-x86_64-unknown-linux-gnu.tar.xz
    rust-1.46.0-x86_64-unknown-linux-gnu.tar.xz
    ...

This makes it really hard to get the package URL without having access to the manifest (and there is no manifest on ci-artifacts.rlo), as there is no consistent version number to use.

This PR addresses the problem by always using the Rust version number as `{release}` for the stable channel, regardless of the version number of the component we're shipping. I chose that instead of "stable" to avoid breaking the URL scheme *that* much.

Rustup should not be affected by this change, as it fetches the URLs from the manifest. Unfortunately we don't have a way to test other clients before making a stable release, as this change only affects the stable channel.

r? `@Mark-Simulacrum`

Make src/bootstrap/CHANGELOG.md more helpful

Addresses https://github.com/rust-lang/rust/commit/fe6fc555acd51bd7ba8755d9fbc7060feb67be25#r42949241.

r? `@RalfJung`
cc `@Mark-Simulacrum`

Add c as a shorthand check alternative for new options #77603

There is a missing "c" that is a shorthand for "check" in newly added match arm for handling check-specific options.

Fix suggestions for x.py setup

#76631 introduced a new `setup` command to x.py

By default the command prompts for a profile to use:

```
Welcome to the Rust project! What do you want to do with x.py?
a) Contribute to the standard library
b) Contribute to the compiler
c) Contribute to the compiler, and also modify LLVM or codegen
d) Install Rust from source
```

and then displays command suggestions, depending on which profile was chosen. However [the mapping between chosen profile](https://github.com/rust-lang/rust/blob/9cba260df0f1c67ea3690035cd5611a7465a1560/src/bootstrap/setup.rs#L75-L85) and [suggestion](https://github.com/rust-lang/rust/blob/9cba260df0f1c67ea3690035cd5611a7465a1560/src/bootstrap/setup.rs#L42-L47) isn't exact, leading to suggestions not being shown if the user presses `c` or `d`. (because "c" is translated to "llvm" and "d" to "maintainer", but suggestions trigger for "codegen" and "user" respectively)

A more thorough refactor would stop using "strings-as-type" to make sure this kind of error doesn't happen, but it may be overkill for that kind of "script" program?

Tagging the setup command author: @jyn514

Add a command to install a git hook to automatically run `x.py test tidy --bless`

Some folks (such as myself) would probably find a lot of convenience in a pre-commit hook that automatically runs tidy before committing, to avoid burning CI time learning that your commit wasn't tidy.

I'm absolutely positive I have missed some stuff. I basically just got this to where you can run `./x.py run install-git-hook` and then clicked the commit button. Please let me know what else you'd like me to add before this can be merged!

[rustc-dev-guide companion PR](https://github.com/rust-lang/rustc-dev-guide/pull/848)