Add test for wide character search

test/terminal/terminal_search_test.dart

@@ -66,6 +66,22 @@ void main() {
       expect(result.allHits[0].endIndex, 11);
     });
 
+    test('Wide character search works', () {
+      final fixture = _TestFixture();
+      fixture.expectTerminalSearchContent(['🍏🍎🍐🍊🍋🍌🍉🍇🍓🫐🍈🍒🍑']);
+      final task = fixture.uut.createSearchTask('testsearch');
+      task.isActive = true;
+      task.pattern = '🍋';
+      task.options = TerminalSearchOptions(
+          caseSensitive: false, matchWholeWord: false, useRegex: false);
+      final result = task.searchResult;
+      expect(result.allHits.length, 1);
+      expect(result.allHits[0].startLineIndex, 0);
+      expect(result.allHits[0].startIndex, 8);
+      expect(result.allHits[0].endLineIndex, 0);
+      expect(result.allHits[0].endIndex, 10);
+    });
+
     test('Finding strings directly on line break works', () {
       final fixture = _TestFixture();
       fixture.expectTerminalSearchContent([