Add Playwright end to end testing (#11912)

* Install playwright

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Add foundations for writing tests under Playwright

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* .gitignore juggling

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Add tsconfig and fix eslint rules

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

playwright.config.ts

@@ -0,0 +1,39 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import type { PlaywrightTestConfig } from "@playwright/test";
+
+const baseURL = process.env["BASE_URL"] ?? "http://localhost:8080";
+
+const config: PlaywrightTestConfig = {
+    use: {
+        headless: false,
+        viewport: { width: 1280, height: 720 },
+        ignoreHTTPSErrors: true,
+        video: "on-first-retry",
+        baseURL,
+    },
+    webServer: {
+        command: process.env.CI ? "npx serve -p 8080 -L ../webapp" : "yarn --cwd ../element-web start",
+        url: `${baseURL}/config.json`,
+        reuseExistingServer: true,
+    },
+    testDir: "playwright/e2e",
+    outputDir: "playwright/test-results",
+    workers: 1,
+    reporter: process.env.CI ? "blob" : [["html", { outputFolder: "playwright/html-report" }]],
+};
+export default config;