v0.0.1 Frontend API

## Background

Currently many custom nodes break during ComfyUI updates because they are using functions where the implementation or definition changes. This occurs in both the frontend and backend. Our goal is to provide a Python and JS API that is backwards compatible and stable for node developers to use.

[More info](https://blog.comfy.org/i/165338805/curated-api-for-backward-compatibility)

## In Scope

- Ship v0.0.1 of the Open-Source frontend API with backward-compatibility support
- Explicit extension points
- Should be Vue agnostic if possible