feat: add more e2e tests for MPR and add test mode and extension (#3180)

* tests: add various e2e tests for MPR and measurements

wip

add cypress config

feat: add mode and extension for testing

add hp applied through search params

add MPR tests

apply review comments

add more e2e tests

update yarn lock

* fix unit tests failing

extensions/test-extension/.webpack/webpack.dev.js

@@ -0,0 +1,8 @@
+const path = require('path');
+const webpackCommon = require('./../../../.webpack/webpack.commonjs.js');
+const SRC_DIR = path.join(__dirname, '../src');
+const DIST_DIR = path.join(__dirname, '../dist');
+
+module.exports = (env, argv) => {
+  return webpackCommon(env, argv, { SRC_DIR, DIST_DIR });
+};