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/playwright/lib/rollup.config.js

@@ -0,0 +1,41 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import typescript from '@rollup/plugin-typescript';
+import copy from 'rollup-plugin-copy';
+
+export default {
+    input: 'src/index.ts',
+    output: [
+        {
+            dir: 'dist',
+            format: 'cjs', // CommonJS for Playwright
+            sourcemap: true,
+            preserveModules: true, // Keep file structure
+            preserveModulesRoot: 'src',
+        },
+    ],
+    plugins: [
+        typescript(),
+        copy({
+            targets: [{src: 'src/asset/**/*', dest: 'dist/asset'}], // Copy assets to dist/
+        }),
+    ],
+    external: [
+        '@playwright/test',
+        '@mattermost/client',
+        '@mattermost/types/config',
+        '@axe-core/playwright',
+        '@percy/playwright',
+        'dotenv',
+        'node:fs/promises',
+        'node:path',
+        'node:fs',
+        'node:os',
+        'mime-types',
+        'uuid',
+        'async-wait-until',
+        'chalk',
+        'deepmerge',
+    ],
+};