* If no version is matching => we print out a message (like we used to)
* If only one version is matching (because the user provided a specific version `6.17.1` or because the prefix match only one installed version) => the version get uninstalled
* If multiple installed versions are matched: we print out the matching installed versions and ask the user to re-run the command with the correct version to uninstall.
Note: it's not possible to uninstall using `latest` or `latest-v9.x`, ... But that's already the case so nothing has changed here.
Seems that Lwt 5 throws a weird error when using `exit(1)` inside a
promise. So instead of exiting in the command, making all executable
modules a function that returns a `result((), status_code)` is a better fit.
Relates to: https://github.com/ocsigen/lwt/issues/758
Corentin Leruth