Make autocomplete work with all known users not just contacts

lib/controls/autocomplete/mention_autocomplete_options.dart

@@ -17,13 +17,7 @@ class MentionAutocompleteOptions extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final users = getIt<ConnectionsManager>().getMyContacts().where((it) {
-      final normalizedHandle = it.handle.toLowerCase();
-      final normalizedName = it.name.toLowerCase();
-      final normalizedQuery = query.toLowerCase();
-      return normalizedHandle.contains(normalizedQuery) ||
-          normalizedName.contains(normalizedQuery);
-    });
+    final users = getIt<ConnectionsManager>().getKnownUsersByName(query);
 
     if (users.isEmpty) return const SizedBox.shrink();
 
@@ -46,7 +40,7 @@ class MentionAutocompleteOptions extends StatelessWidget {
             ),
           ),
           LimitedBox(
-            maxHeight: MediaQuery.of(context).size.height * 0.3,
+            maxHeight: MediaQuery.of(context).size.height * 0.2,
             child: ListView.separated(
               padding: EdgeInsets.zero,
               shrinkWrap: true,

lib/services/connections_manager.dart

@@ -38,6 +38,16 @@ class ConnectionsManager extends ChangeNotifier {
     return updateConnection(connection);
   }
 
+  List<Connection> getKnownUsersByName(String name) {
+    return _connectionsByName.values.where((it) {
+      final normalizedHandle = it.handle.toLowerCase();
+      final normalizedName = it.name.toLowerCase();
+      final normalizedQuery = name.toLowerCase();
+      return normalizedHandle.contains(normalizedQuery) ||
+          normalizedName.contains(normalizedQuery);
+    }).toList();
+  }
+
   bool updateConnection(Connection connection) {
     _connectionsById[connection.id] = connection;
     _connectionsByName[connection.name] = connection;