Merge branch 'krille/wait-for-devicekeys' into 'main'

chore: Make sure account data and device keys is loaded when using isCached

See merge request famedly/company/frontend/famedlysdk!1037

lib/encryption/key_manager.dart

@@ -558,6 +558,8 @@ class KeyManager {
     if (!enabled) {
       return false;
     }
+    await client.accountDataLoading;
+    await client.userDeviceKeysLoading;
     return (await encryption.ssss.getCached(megolmKey)) != null;
   }