Update clap + fixes.

[emilio]

Work in progress for now.

[wiktor-k]

I'd be good to have this PR merged since the old clap depends on things which have issues:

$ cargo deny check
warning[A004]: Potential unaligned read
  │
3 │ atty 0.2.14 registry+https://github.com/rust-lang/crates.io-index
  │ ----------------------------------------------------------------- unsound advisory detected
  │
  = ID: RUSTSEC-2021-0145
  = Advisory: https://rustsec.org/advisories/RUSTSEC-2021-0145
  = On windows, `atty` dereferences a potentially unaligned pointer.
    
    In practice however, the pointer won't be unaligned unless a custom global allocator is used.
    
    In particular, the `System` allocator on windows uses `HeapAlloc`, which guarantees a large enough alignment.
    
    # atty is Unmaintained
    
    A Pull Request with a fix has been provided over a year ago but the maintainer seems to be unreachable.
    
    Last release of `atty` was almost 3 years ago.
    
    ## Possible Alternative(s)
    
    The below list has not been vetted in any way and may or may not contain alternatives;
    
     - [std::io::IsTerminal](https://doc.rust-lang.org/stable/std/io/trait.IsTerminal.html) - Stable since Rust 1.70.0
     - [is-terminal](https://crates.io/crates/is-terminal) - Standalone crate supporting Rust older than 1.70.0
  = Announcement: https://github.com/softprops/atty/issues/50
  = Solution: No safe upgrade is available!
  = atty v0.2.14
    └── clap v3.2.25
        └── cbindgen v0.26.0

Is there anything blocking this? Except for the formatting and clippy which look not-so-hard to resolve.