MM-62954 E2E/Playwright shared library (#30177)

* feat: Add package.json for Playwright library with dependencies

* feat: Add explicit exports for test.config in playwright-lib package

* feat: Add initialization setup for Mattermost E2E testing with admin and user client

* fix: Update package dependencies and resolve TypeScript build errors

* feat: Update package exports for test.config to support both CommonJS and ESM

* playwright shared library

* add README, fix pipeline

* keep file structures, move report up to playwright

* minimize API, use the prerelease versions of client and types

* bump version

* update package*.json

* resolve merge conflict

* update depedencies and merge conflicts

* update readme and fix ci

* remove unnecessary export and list all external packages

* fix import for Client4

e2e-tests/.ci/report.publish.sh

@@ -105,7 +105,7 @@ case "$TEST" in
     if [ -n "$WEBHOOK_URL" ]; then
       PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 npm i
       # Utilize environment data and report files to generate the webhook body
-      ./report.webhookgen.js | curl -X POST -fsSL -H 'Content-Type: application/json' -d @- "$WEBHOOK_URL"
+      node report.webhookgen.js | curl -X POST -fsSL -H 'Content-Type: application/json' -d @- "$WEBHOOK_URL"
     fi
     ;;
 esac