Move CliRepl into main package and adapt it's API to be suitable for Node.js too

[carnesen]

The CliRepl in the cli-website module has really worked out well. The autocompletion is super slick. That feature is worthy of promotion to the main module @carnesen/cli and it should be possible too since we only lightly use the Terminal interface from XTerm.js. To do so we need to make CliRepl pure dependency-free JavaScript and suitable for Node.js too. Probably it should just be an ordinary object factory too like CliBranch etc. instead of a class like it is today.

Use cases:

• Browser: Dedicated browser CLIs like https://cli.carnesen.com
• Node.js: my-cli repl: The CliRepl autocompletion is really good and useful even when we have productized shell autocompletion. There will be really slick things we can do in the custom REPL that wouldn't be possible in a normal shell REPL. Think of it like the mysql or redis-cli REPLs.