feat: suggest common mistaken subcommands

[amoeba]

This PR adds a way for dbc to suggest commands when the user enters a command
that doesn't exist. It adds a hook to our argument parser's error handler to
augment the error message with a suggestion.

I started with list -> search because I notice that users and/or AI agents like
to hallucinate 'dbc list' and I think this will help by at least reducing the
number of turns it takes for the agent to learn about dbc search.

We might consider a fuzzy suggestion feature (saerch -> search) like other CLI
tools use as a follow-on to this.

[amoeba]

Happy to take ideas on the look of this,

$ ./dbc list
Usage: dbc [--quiet] <command> [<args>]
error: invalid subcommand: list. Did you mean: dbc search?

[amoeba]

I'd like to put the change for printing help text from stdout to stderr in another PR so I addressed just the newline.

@zeroshade did you have any thoughts on the look or wording?