Implement support for installing ComfyUI as a pip package

I'm interested in using some of ComfyUI's internal nodes programmatically, in the context of another python project.
For this purpose, it would be beneficial to have an option to install ComfyUI as a standard python package, e.g. `pip install comfyui`.

This could also be used to simplify the installation process for end users, i.e. instead of having to clone and repo and manually installing the requirements, one could do something like:
```
pip install comfyui
comfy run [args]
```

What do you think?