Adds playwright test command

Adds a new npm script for running Playwright tests.

This allows for easier execution of end-to-end tests using Playwright.

package.json

@@ -8,7 +8,8 @@
     "build": "vue-cli-service build",
     "test:unit": "vue-cli-service test:unit --coverage --ci",
     "test:unit:lite": "vue-cli-service test:unit --ci",
-    "lint": "vue-cli-service lint"
+    "lint": "vue-cli-service lint",
+    "test:playwright": "playwright test --config=playwright-tests/playwright.config.ts"
   },
   "dependencies": {
     "@iframe-resizer/child": "^5.3.3",