feat: add ability to add several items to a dictionary list at a time

lib/src/dao/my_dictionary_lists_dao.dart

@@ -111,6 +111,33 @@ class MyDictionaryListsDao extends DatabaseAccessor<AppDatabase>
     });
   }
 
+  Future<void> addDictionaryItems(
+    MyDictionaryList dictionaryList,
+    List<DictionaryItem> dictionaryItems,
+  ) async {
+    final items = dictionaryItems.map((item) {
+      final vocabId = item is Vocab ? item.id : 0;
+      final kanjiId = item is Kanji ? item.id : 0;
+      return MyDictionaryListItemsCompanion(
+        listId: Value(dictionaryList.id),
+        vocabId: Value(vocabId),
+        kanjiId: Value(kanjiId),
+      );
+    }).toList();
+
+    await transaction(() async {
+      for (final item in items) {
+        await db
+            .into(db.myDictionaryListItems)
+            .insert(item, mode: InsertMode.insertOrIgnore);
+      }
+
+      await (db.update(db.myDictionaryLists)
+            ..where((list) => list.id.equals(dictionaryList.id)))
+          .write(MyDictionaryListsCompanion(timestamp: Value(DateTime.now())));
+    });
+  }
+
   Future<void> removeDictionaryItem(
     MyDictionaryList dictionaryList,
     DictionaryItem dictionaryItem,

test/dao/my_dictionary_lists_dao_test.dart

@@ -167,7 +167,7 @@ void main() {
       expect(newFlashcardSets[0].myDictionaryLists.length, 0);
     });
 
-    test('Dictionary items', () async {
+    test('Dictionary item operations', () async {
       final dictionaryList1 =
           await database.myDictionaryListsDao.create('list1');
       final dictionaryList2 =
@@ -241,6 +241,52 @@ void main() {
       expect(list2Items.kanjiIds.length, 0);
     });
 
+    test('addDictionaryItems', () async {
+      final dictionaryList = await database.myDictionaryListsDao.create('list');
+
+      // Get empty items
+      final emptyList1Items = await database.myDictionaryListsDao
+          .getDictionaryListItems(dictionaryList);
+      expect(emptyList1Items.vocabIds.length, 0);
+      expect(emptyList1Items.kanjiIds.length, 0);
+
+      // Add items to dictionary list
+      await database.myDictionaryListsDao.addDictionaryItem(
+        dictionaryList,
+        await database.vocabsDao.get(1000220),
+      );
+      await database.myDictionaryListsDao.addDictionaryItem(
+        dictionaryList,
+        await database.vocabsDao.get(1003430),
+      );
+
+      // Get newly added to list
+      var listItems = await database.myDictionaryListsDao
+          .getDictionaryListItems(dictionaryList);
+      expect(listItems.vocabIds.length, 2);
+      expect(listItems.vocabIds[0], 1003430);
+      expect(listItems.vocabIds[1], 1000220);
+
+      // Add several items at once
+      await database.myDictionaryListsDao.addDictionaryItems(
+        dictionaryList,
+        [
+          await database.vocabsDao.get(1000160),
+          await database.vocabsDao.get(1003430),
+          await database.vocabsDao.get(1001390),
+        ],
+      );
+
+      // Check new contents
+      listItems = await database.myDictionaryListsDao
+          .getDictionaryListItems(dictionaryList);
+      expect(listItems.vocabIds.length, 4);
+      expect(listItems.vocabIds[0], 1001390);
+      expect(listItems.vocabIds[1], 1000160);
+      expect(listItems.vocabIds[2], 1003430);
+      expect(listItems.vocabIds[3], 1000220);
+    });
+
     test('getContainingDictionaryItem', () async {
       final dictionaryList1 =
           await database.myDictionaryListsDao.create('list1');