Revert "Babel: use babel-loader instead of ts-loader, ng-annotate with babel-plugin-angularjs-annotate (#21554)" (#21570)

This reverts #21554 which caused problems with e2e.
This reverts commit e7e0d18bc8.

package.json

@@ -9,13 +9,11 @@
     "url": "http://github.com/grafana/grafana.git"
   },
   "devDependencies": {
-    "@babel/core": "7.8.3",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "7.8.3",
-    "@babel/plugin-proposal-optional-chaining": "7.8.3",
-    "@babel/plugin-syntax-dynamic-import": "7.8.3",
+    "@babel/core": "7.6.4",
+    "@babel/plugin-syntax-dynamic-import": "7.2.0",
     "@babel/preset-env": "7.6.3",
     "@babel/preset-react": "7.6.3",
-    "@babel/preset-typescript": "7.8.3",
+    "@babel/preset-typescript": "7.6.0",
     "@emotion/core": "10.0.10",
     "@rtsao/plugin-proposal-class-properties": "7.0.1-patch.1",
     "@testing-library/react-hooks": "^3.2.1",
@@ -107,6 +105,8 @@
     "mocha": "4.1.0",
     "module-alias": "2.2.0",
     "monaco-editor": "0.15.6",
+    "ng-annotate-loader": "0.6.1",
+    "ng-annotate-webpack-plugin": "0.3.0",
     "ngtemplate-loader": "2.0.1",
     "node-sass": "4.12.0",
     "npm": "6.13.4",