Block Editor: Add a script to run Gutenberg end 2 end tests on Core.

The script is not part of CI yet because the job takes 40mn to run
and it's not useful in all PRs/commits.

Fixes #50469.


git-svn-id: https://develop.svn.wordpress.org/trunk@48382 602fd350-edb4-49c9-b593-d223f7449a82

package.json

@@ -31,6 +31,7 @@
 		"@wordpress/library-export-default-webpack-plugin": "1.7.0",
 		"@wordpress/scripts": "12.1.0",
 		"autoprefixer": "9.6.2",
+		"chalk": "4.1.0",
 		"check-node-version": "4.0.1",
 		"copy-webpack-plugin": "^5.1.1",
 		"cssnano": "4.1.10",
@@ -71,6 +72,7 @@
 		"source-map-loader": "^0.2.4",
 		"uglify-js": "^3.6.0",
 		"uglifyjs-webpack-plugin": "2.2.0",
+		"uuid": "8.2.0",
 		"wait-on": "3.3.0",
 		"webpack": "4.43.0",
 		"webpack-dev-server": "3.11.0",