Auto merge of #8542 - CPerezz:aliases, r=ehuss

Auto merge of #8542 - CPerezz:aliases, r=ehuss

Display builtin aliases with `cargo --list`

As stated in #8486 it would help to the discovery of the
builtin aliases the facto of printing them with the
`cargo --list` command.

- Extracted the builtin aliases currently implemented to a
separated `const`.
- Make all of the functions that interact with these aliases
point to that function.
- Refactored the `list_commands` fn in order to include with the
builtin and external commands, the builtin aliases that come with
cargo by default.
- Added a test that checks that the aliases that currently
are builtin with cargo are indeed being printed with the rest
of the commands when `cargo --list` is called.

The output on my machine looks like this:
```
$ cargo --list
Installed Commands:
    b                    alias: build
    bench                Execute all benchmarks of a local package
    build                Compile a local package and all of its dependencies
    c                    alias: check
    check                Check a local package and all of its dependencies for errors
    clean                Remove artifacts that cargo has generated in the past
    doc                  Build a package's documentation
    fetch                Fetch dependencies of a package from the network
    fix                  Automatically fix lint warnings reported by rustc
    generate-lockfile    Generate the lockfile for a package
    git-checkout         This subcommand has been removed
    init                 Create a new cargo package in an existing directory
    install              Install a Rust binary. Default location is $HOME/.cargo/bin
    locate-project       Print a JSON representation of a Cargo.toml file's location
    login                Save an api token from the registry locally. If token is not specified, it will be read from stdin.
    metadata             Output the resolved dependencies of a package, the concrete used versions including overrides, in machine-readable format
    new                  Create a new cargo package at <path>
    owner                Manage the owners of a crate on the registry
    package              Assemble the local package into a distributable tarball
    pkgid                Print a fully qualified package specification
    publish              Upload a package to the registry
    r                    alias: run
    read-manifest        Print a JSON representation of a Cargo.toml manifest.
    run                  Run a binary or example of the local package
    rustc                Compile a package, and pass extra options to the compiler
    rustdoc              Build a package's documentation, using specified custom flags.
    search               Search packages in crates.io
    t                    alias: test
    test                 Execute all unit and integration tests and build examples of a local package
    tree                 Display a tree visualization of a dependency graph
    uninstall            Remove a Rust binary
    update               Update dependencies as recorded in the local lock file
    vendor               Vendor all dependencies for a project locally
    verify-project       Check correctness of crate manifest
    version              Show version information
    yank                 Remove a pushed crate from the index
    clippy
    clippy
    clippy
    clippy
    flamegraph
    fmt
    fmt
    fmt
    fmt
    miri
    miri
    miri
    miri
    outdated
    tree
```

As discussed with @ehuss the `BTreeSet` enforces `Ord` therefore, the aliases get mixed with the commands since they're passed through the same function.

It can be refactored to appear separately, but, the code will be more spread and now it's all in just one file (which I believe is easier to maintain and review).

Closes #8486