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

plugins/course-apps/learning_assistant/package.json

@@ -0,0 +1,19 @@
+{
+    "name": "@openedx-plugins/course-app-learning_assistant",
+    "version": "0.1.0",
+    "description": "Learning Assistant configuration for courses using it",
+    "peerDependencies": {
+        "@edx/frontend-app-course-authoring": "*",
+        "@edx/frontend-platform": "*",
+        "@openedx/paragon": "*",
+        "prop-types": "*",
+        "react": "*",
+        "yup": "*"
+    },
+    "peerDependenciesMeta": {
+        "@edx/frontend-app-course-authoring": {
+            "optional": true
+        }
+    }
+}
+