Optimize zkVM code for faster proof generation

[mohamedalichelbi]

• Some things to try: RISC0 Quick wins
• Extract only used attributes from credential objects, and pass that to the zkVM (or the scripting engine, depending on the bottle-neck). The most easy/naive way for this is to extract all first-level credential object keys, and check which ones appear in the script using one regex containing all those keys. From there remove all keys that have no matches. A more sophisticated solution would be to run the script outside of the zkVM and check what attributes exactly were accesses by the script, this would allow extracting exactly the needed value and nothing more, even for multiple levels of nesting.
• Profile guest code: It is important to know exactly what operations are most costly in terms of number of cycles. There are multiple profilers to try, like this or this
• RISC0 has RISC0_DEV_MODE=1 which allows for faster iterations by just running the guest code without proving it.