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/config/ConfigOptions.ts

@@ -1,6 +1,7 @@
 export interface IConfigOptions {
   posthog?: {
     api_key: string;
+    api_host: string;
   };
   sentry?: {
     DSN: string;