CLI autocompletions

### Feature description

We discussed a bit offline and came up to the conclusion that in the future it'd be nice to have shell autocompletions in the CLI. It's not prioritary at all, just more of a nth.

Doing some quick research I found that clap 2 had support for autocompletions, and on clap 3 they extracted a [crate](https://docs.rs/clap_complete/latest/clap_complete/) for that to avoid bloat. I also found [this useful blog post](https://kbknapp.dev/shell-completions/)that goes a bit into what it takes to either generate completions on build time or during runtime.

### Why is this feature needed?

It would improve UX