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

jest.config.js

@@ -11,6 +11,7 @@ module.exports = createConfig('jest', {
   ],
   moduleNameMapper: {
     '^lodash-es$': 'lodash',
+    '^CourseAuthoring/(.*)$': '<rootDir>/src/$1',
   },
   modulePathIgnorePatterns: [
     '/src/pages-and-resources/utils.test.jsx',