Improve how extension-api is exposed/loaded (#1055)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

src/renderer/bootstrap.tsx

@@ -1,5 +1,7 @@
 import "./components/app.scss"
 import React from "react";
+import * as Mobx from "mobx"
+import * as LensExtensions from "../extensions/extension-renderer-api"
 import { render, unmountComponentAtNode } from "react-dom";
 import { isMac } from "../common/vars";
 import { userStore } from "../common/user-store";
@@ -14,6 +16,12 @@ type AppComponent = React.ComponentType & {
   init?(): void;
 }
 
+export {
+  React,
+  Mobx,
+  LensExtensions
+}
+
 export async function bootstrap(App: AppComponent) {
   const rootElem = document.getElementById("app")
   rootElem.classList.toggle("is-mac", isMac);