wrap-up list module, enable tests when possible.

  Few TODOs from there:

  - [] Seems like the parser can't parse negative literals.
    Current work-around: write as `0 - n` instead of `-n`.

  - [] The formatter confuses tuples with function arguments
    in expression blocks. So writing:

    ```
    let (xs, ys) = unzip(rest)
    ([x, ..xs], [y, ..ys])
    ```

    is wrongly turned into:

    ```
    let (xs, ys) = unzip(rest)([x, ..xs], [y, ..ys])
    ```

  - [] Inline comments and function documentation comments are wrongly
    grouped together by the formatter.

  - [] The compiler panicks when two tests have the same name:

    ```
    test foo() { todo }
    test foo() { todo }
    ```

    ```
    Error:
      × Main thread panicked.
      ├─▶ at crates/lang/src/tipo/infer.rs:181:43
      ╰─▶ Could not find hydrator for fn
      help: set the `RUST_BACKTRACE=1` environment variable to display a backtrace.
    ```

  - As well as any acceptance tests added to: aiken-lang/aiken#166