implement per-event state filtering for invited rooms on /sync

This one is a little weird, because the stripped invite state events are
not deserialized.

src/api/client_server/sync.rs

@@ -262,9 +262,14 @@ pub(crate) async fn sync_events_route(
             continue;
         }
 
+        let state_events = invite_state_events
+            .into_iter()
+            .filter(|event| compiled_filter.room.state.raw_event_allowed(event))
+            .collect();
+
         let invited_room = InvitedRoom {
             invite_state: InviteState {
-                events: invite_state_events,
+                events: state_events,
             },
         };
         if !invited_room.is_empty() {