Fitz CLI builder: like typer, but in the language

Fitz CLI builder is a new way to build native CLI tools in the same language that powers HTTP services, eliminating the need for external libraries and providing a more native experience. This is particularly appealing as it allows for the same compiler, type checker, and async/await syntax to be used for both HTTP services and CLI tools. Fitz CLI builder uses a convention-based approach to handle positional arguments and flags, reducing verbosity and making it easier to build CLI tools.