feat: implement generator for named annotation

cherrypick_annotations/lib/cherrypick_annotations.dart

@@ -7,5 +7,6 @@ export 'src/module.dart';
 export 'src/bind.dart';
 export 'src/provide.dart';
 export 'src/singleton.dart';
+export 'src/named.dart';
 
 // TODO: Export any libraries intended for clients of this package.

cherrypick_annotations/lib/src/named.dart

@@ -0,0 +1,5 @@
+// ignore: camel_case_types
+class named {
+  final String value;
+  const named(this.value);
+}