[CLI] Investigate/cleanup help option

[JonasCir]

Not certain how this is supposed to work: We always define the Help variant in commands in src/cli/mod.rs but do not match it in main.rs. I would assume that we can get rid of this variant and just let do clap its magic when an unknown command is encountered.

Probably something along these lines.

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Edit: I just found #[clap(arg_required_else_help = true)].
Edit 2: we should bump clap to the most recent version