✨ (cli): Add support for interactive CLI input

[raxhvl]

The CLI is the primary interface of the framework. A standalone, interactive CLI input system can help automate common tasks (see #926) and guide new users through features like gentest as it grows to become sophisticated.

One challenge with this is selecting the right library to handle user input. We should create a package to wrap a library like questionary under the hood, while providing an easily swappable interface for future changes.