Add initial set of Playwright integration tests, for testing embeds (#254)

* add first pass on playwright integration tests!
- test embed loading via localhost:9990/embed.html as well as cross-domain with embed on localhost:8020/
while RWP + data on localhost:9990/
- add --ignore-optional to most ci runs
- add playwright ci test
- add playwright and playwright-test to dev dependencies
- add 'test-start-embed' to start test harness for localhost:8020/ embed
- add 'test-start-sandbox' to start test harndess for localhost:8030/ sandbox
- add additional tests for loading with sandbox + requiresubdomainiframe, ensure 'requiresubdomainiframe' works, doesn't allow loading directly

package.json

@@ -28,6 +28,7 @@
     "stream-browserify": "^3.0.0"
   },
   "devDependencies": {
+    "@playwright/test": "^1.38.1",
     "copy-webpack-plugin": "^9.0.1",
     "css-loader": "^6.2.0",
     "electron": "^25.1.1",
@@ -41,6 +42,7 @@
     "lint-staged": "^14.0.0",
     "mini-css-extract-plugin": "^2.3.0",
     "node-sass": "^9.0.0",
+    "playwright": "^1.38.1",
     "prettier": "^3.0.1",
     "raw-loader": "^4.0.2",
     "sass-loader": "^13.3.2",
@@ -64,7 +66,9 @@
     "build-dev": "webpack --mode development",
     "build-docs": "bundle install; bundle exec jekyll build",
     "start-dev": "webpack serve --mode development",
-    "start-prod": "http-server -p 9990",
+    "start-prod": "http-server -p 9990 --cors",
+    "test-start-embed": "cd tests/embed; http-server -p 8020",
+    "test-start-sandbox": "cd tests/embed/sandbox; http-server -p 8030",
     "pack": "CSC_IDENTITY_AUTO_DISCOVERY=false electron-builder --publish never",
     "pack-signed": "electron-builder",
     "start-electron": "NODE_ENV=development electron ./dist/electron.js $1",