Better errors when using ctx outside action or component

[coffee-cup]

If you have the transpiler setup and have

import { state } from "./model";

console.log(state.foo);

const myAction = () => {
  state.foo += 1;
}

you will get a runtime error say that you can't read foo of undefined. Instead of removing the state import after transpilation, we should keep it and make everything on the imported ctx a proxy that will show a nice error message.