Convert "Pages & Resources" page to a plugin system (#638)

* feat: Make "Pages & Resources" course apps into plugins

* feat: move ora_settings

* feat: move proctoring

* feat: move progress

* feat: move teams

* feat: move wiki

* feat: move Xpert settings

* fix: add webpack.prod.config.js

* fix: clean up unused parts of package.json files

* feat: Add an error message when displaying a Course App Plugin fails

* chore: fix various eslint warnings

* chore: fix jest tests

* fix: error preventing "npm ci" from working

* feat: better tests for <SettingsComponent>

* chore: move xpert_unit_summary into same dir as other plugins

* fix: eslint-import-resolver-webpack is a dev dependency

* chore: move learning_assistant to be a plugin too

* feat: for compatibility, install 2U plugins by default

* fix: bug with learning_assistant package.json

webpack.dev.config.js

@@ -1,7 +1,12 @@
+const path = require('path');
 const { createConfig } = require('@openedx/frontend-build');
 
 const config = createConfig('webpack-dev', {
   resolve: {
+    alias: {
+      // Plugins can use 'CourseAuthoring' as an import alias for this app:
+      CourseAuthoring: path.resolve(__dirname, 'src/'),
+    },
     fallback: {
       fs: false,
       constants: false,