Add E2E status in room header (#11493)

* Add E2E status in room header

* Clearer logic for dmRoomList

Co-authored-by: Andy Balaam <andy.balaam@matrix.org>

* Add test for E2E shield

* Remove dead code

---------

Co-authored-by: Andy Balaam <andy.balaam@matrix.org>

src/i18n/strings/en_EN.json

@@ -1851,6 +1851,7 @@
     "Room %(name)s": "Room %(name)s",
     "Recently visited rooms": "Recently visited rooms",
     "No recently visited rooms": "No recently visited rooms",
+    "Untrusted": "Untrusted",
     "%(count)s members": {
         "other": "%(count)s members",
         "one": "%(count)s member"