refactor: Promote handling unsigned data out of timeline

Also fixes:
- Transaction IDs leaking in event route
- Age not being set for event relations or threads
- Both of the above for search results

Notes down concern with relations table

src/api/client/message.rs

@@ -122,14 +122,14 @@ pub(crate) async fn get_message_events_route(
 		| Direction::Forward => services
 			.rooms
 			.timeline
-			.pdus(Some(sender_user), room_id, Some(from))
+			.pdus(room_id, Some(from))
 			.ignore_err()
 			.boxed(),
 
 		| Direction::Backward => services
 			.rooms
 			.timeline
-			.pdus_rev(Some(sender_user), room_id, Some(from))
+			.pdus_rev(room_id, Some(from))
 			.ignore_err()
 			.boxed(),
 	};
@@ -140,6 +140,11 @@ pub(crate) async fn get_message_events_route(
 		.wide_filter_map(|item| ignored_filter(&services, item, sender_user))
 		.wide_filter_map(|item| visibility_filter(&services, item, sender_user))
 		.take(limit)
+		.then(async |mut pdu| {
+			pdu.1.set_unsigned(Some(sender_user));
+			// TODO: bundled aggregations
+			pdu
+		})
 		.collect()
 		.await;