Implement state transitions into Rust sdk

[slundqui]

Add a state transition function when calling e.g., open long in rust. For example, calculate_open_long also returns an updated pool state after the trade. This would allow simulations to bypass the anvil bottleneck to substantially speed up simulations.

[jalextowle]

This relates to #23. The easiest way to update the SDK with that in mind would be to:

1. Attempt to apply the latest checkpoint
2. Apply the operation that should be simulated

[dpaiton]

Partially achieved by adding the state transition functions for
open short #15
open long #68