[Tech]: Start migrating to Jest for tests (#9610)

* tech: investigating karma + jest mix

* tech: migrating tests to jest

* tech: moved anoter test file to jest

* test: migrated two more test files to jest

* test: updated readme and made test fail to verify that it causes CI build failure

* tech: added code coverage for jest tests

* tech: testing codecov coverage

* tech: migrated more tests

* tech: migrated template srv to typescript and the tests to jest

* tech: minor build fix

* tech: build fixes

* build: another attempt at fixing go test with coverage

scripts/webpack/webpack.prod.js

@@ -26,6 +26,10 @@ module.exports = merge(common, {
     ]
   },
 
+  devServer: {
+    stats: 'errors-only',
+  },
+
   plugins: [
     new ExtractTextPlugin({
       filename: 'grafana.[name].css',