Rename _display to displayList

lib/screens/characters_list_screen.dart

@@ -12,7 +12,7 @@ class CharactersListScreen extends StatefulWidget {
 
 class _CharactersListScreenState extends State<CharactersListScreen> {
   List<Character>? characters; // Full list for display
-  List<Character>? _display; // List to display
+  List<Character>? displayList; // List to display
 
   @override
   void initState() {
@@ -29,7 +29,7 @@ class _CharactersListScreenState extends State<CharactersListScreen> {
         });
       });
     }
-    this._display = characters;
+    this.displayList = characters;
 
     super.initState();
   }
@@ -58,7 +58,7 @@ class _CharactersListScreenState extends State<CharactersListScreen> {
     ];
 
     setState(() {
-      _display = _filterList;
+      displayList = _filterList;
     });
   }
 
@@ -86,7 +86,7 @@ class _CharactersListScreenState extends State<CharactersListScreen> {
                 child: ListView.separated(
                   itemBuilder: (context, index) => _buildCharacterListTile(index),
                   separatorBuilder: (_, __) => Divider(),
-                  itemCount: _display?.length ?? 0,
+                  itemCount: displayList?.length ?? 0,
                 ),
               ),
             ],
@@ -97,7 +97,7 @@ class _CharactersListScreenState extends State<CharactersListScreen> {
   }
 
   Widget _buildCharacterListTile(int index) {
-    final Character character = _display![index];
+    final Character character = displayList![index];
     return ListTile(
       title: Text(
         '${index + 1}. ${character.name}',