feat: Add async builders for view_* functions

[ChaoticTempest]

This adds the async builder Query which allows doing view calls into contract state, account, access keys, code, the view function call, and block. This uses IntoFuture to allow calling into .await at any point in the builder. Note, that Query builder takes a generic <T> for the method like ViewState since we can define custom builder functions per method type by doing impl Query<ViewState> { ... }

cc @matklad if you want to review my use of IntoFuture since you initially suggested it

[matklad]

IntoFuture stuff looks correct to me.

What caught my eye is that we are enduring some pain (and even causing the users paint) to be generic over &str vs String. Did we measured that using &str gives us a measurable performance improvements? If we did not, I suggest sticking with owned String and clone, and removing extra generics from the API.