Gremlin: Enhance performance of reuse graph traversal source

[chungquantin]

Is your feature request related to a problem? Please describe.

let t1 = db
		.traverse()
		.v(1)
		.add_v("person")
		.property("github", "tin-snowflake")
		.property("name", "Tin Chung")
		.property("age", 21)
		.add_v("coder")
		.property("github", "chungquantin")
		.property("age", 30);

let t2 = t1.clone().has_key("github").has_label("person").exec().to_list().await.unwrap();
let t3 = t1.clone().has_key("github").exec().to_list().await.unwrap();
let t4 = t1.clone().has_not("name").exec().next().await.unwrap();

Describe the solution you'd like
For now, query like this is exhaustive. Even though t1 is reused, all steps are handled again whenever t2, t3 or t4 called. Can implement a record checkpoint to enhance the situation