Add posthog Telemetry (Anonymity Logic + call duration telemetry) (#658)

Co-authored-by: Timo K <timok@element.io>
Co-authored-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/auth/LoginPage.tsx

@@ -33,6 +33,7 @@ import { defaultHomeserver, defaultHomeserverHost } from "../matrix-utils";
 import styles from "./LoginPage.module.css";
 import { useInteractiveLogin } from "./useInteractiveLogin";
 import { usePageTitle } from "../usePageTitle";
+import { PosthogAnalytics } from "../PosthogAnalytics";
 
 export const LoginPage: FC = () => {
   const { t } = useTranslation();
@@ -64,6 +65,7 @@ export const LoginPage: FC = () => {
           } else {
             history.push("/");
           }
+          PosthogAnalytics.instance.eventLogin.track();
         })
         .catch((error) => {
           setError(error);