Implemented basic structure

lib/data/db/tables/group_table.dart

@@ -0,0 +1,9 @@
+import 'package:drift/drift.dart';
+
+class GroupTable extends Table {
+  TextColumn get id => text()();
+  TextColumn get name => text()();
+
+  @override
+  Set<Column<Object>> get primaryKey => {id};
+}