feat(AppSync): addRdsDataSource support for DatabaseCluster

packages/@aws-cdk-testing/framework-integ/test/aws-appsync/test/appsync.rds-serverlessv2.graphql

@@ -0,0 +1,25 @@
+schema {
+    query: Query
+    mutation: Mutation
+}
+
+type Query {
+    getPost(id:ID!): Post
+    allPosts: [Post]
+}
+
+type Mutation {
+    addPost(id: ID!, author: String!, title: String, content: String, url: String): Post!
+}
+
+type Post {
+    id: ID!
+    author: String!
+    title: String
+    content: String
+    url: String
+    ups: Int
+    downs: Int
+    relatedPosts: [Post]
+    relatedPostsMaxBatchSize: [Post]
+}