Fix E2E tests. Add Playwright (#698)

test/utils/safeClick.ts

@@ -0,0 +1,11 @@
+import { Frame } from "playwright";
+
+export async function safeClick(page: Frame, selector: string): Promise<void> {
+  // TODO: Remove. Playwright does this for you... mostly.
+  // But our knockout+react setup sometimes leaves dom nodes detached and even playwright can't recover.
+  // Resource tree is particually bad.
+  // Ideally this should only be added as a last resort
+  await page.waitForSelector(selector);
+  await page.waitForTimeout(5000);
+  await page.click(selector);
+}