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

yarn.lock

@@ -327,6 +327,13 @@
     tslib "^2.4.1"
     tsyringe "^4.7.0"
 
+"@playwright/test@^1.38.1":
+  version "1.38.1"
+  resolved "https://registry.yarnpkg.com/@playwright/test/-/test-1.38.1.tgz#8ef4263e355cd1d8ad7905d471d268e8acb82ed6"
+  integrity sha512-NqRp8XMwj3AK+zKLbZShl0r/9wKgzqI/527bkptKXomtuo+dOjU9NdMASQ8DNC9z9zLOMbG53T4eihYr3XR+BQ==
+  dependencies:
+    playwright "1.38.1"
+
 "@sindresorhus/is@^0.14.0":
   version "0.14.0"
   resolved "https://registry.yarnpkg.com/@sindresorhus/is/-/is-0.14.0.tgz#9fb3a3cf3132328151f353de4632e01e52102bea"
@@ -2740,7 +2747,7 @@ fs.realpath@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
   integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
 
-fsevents@~2.3.2:
+fsevents@2.3.2, fsevents@~2.3.2:
   version "2.3.2"
   resolved "https://registry.yarnpkg.com/fsevents/-/fsevents-2.3.2.tgz#8a526f78b8fdf4623b709e0b975c52c24c02fd1a"
   integrity sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==
@@ -4618,6 +4625,20 @@ pkg-dir@^4.2.0:
   dependencies:
     find-up "^4.0.0"
 
+playwright-core@1.38.1:
+  version "1.38.1"
+  resolved "https://registry.yarnpkg.com/playwright-core/-/playwright-core-1.38.1.tgz#75a3c470aa9576b7d7c4e274de3d79977448ba08"
+  integrity sha512-tQqNFUKa3OfMf4b2jQ7aGLB8o9bS3bOY0yMEtldtC2+spf8QXG9zvXLTXUeRsoNuxEYMgLYR+NXfAa1rjKRcrg==
+
+playwright@1.38.1, playwright@^1.38.1:
+  version "1.38.1"
+  resolved "https://registry.yarnpkg.com/playwright/-/playwright-1.38.1.tgz#82ecd9bc4f4f64dbeee8a11c31793748e2528130"
+  integrity sha512-oRMSJmZrOu1FP5iu3UrCx8JEFRIMxLDM0c/3o4bpzU5Tz97BypefWf7TuTNPWeCe279TPal5RtPPZ+9lW/Qkow==
+  dependencies:
+    playwright-core "1.38.1"
+  optionalDependencies:
+    fsevents "2.3.2"
+
 plist@^3.0.1, plist@^3.0.4:
   version "3.0.5"
   resolved "https://registry.yarnpkg.com/plist/-/plist-3.0.5.tgz#2cbeb52d10e3cdccccf0c11a63a85d830970a987"