Add support for redirecting to external pages after logout (#7905)

* Add support for redirecting to external pages after logout

This is primarily useful for deployments where the account is managed and needs to be logged out in other places too, like an SSO system.

See docs for more information.

* Add e2e test and fix Windows instructions

* Fix performance gathering stats

* use logger

test/end-to-end-tests/start.ts

@@ -90,6 +90,10 @@ async function runTests() {
         // Collecting all performance monitoring data before closing the session
         const measurements = await session.page.evaluate(() => {
             let measurements;
+
+            // Some tests do redirects away from the app, so don't count those sessions.
+            if (!window.mxPerformanceMonitor) return JSON.stringify([]);
+
             window.mxPerformanceMonitor.addPerformanceDataCallback({
                 entryNames: [
                     window.mxPerformanceEntryNames.REGISTER,
@@ -111,7 +115,7 @@ async function runTests() {
         performanceEntries = JSON.parse(measurements);
         return session.close();
     }));
-    if (performanceEntries) {
+    if (performanceEntries?.length > 0) {
         fs.writeFileSync(`performance-entries.json`, JSON.stringify(performanceEntries));
     }
     if (failure) {