(VME) [Spike] Review Nitro Enclave API

[BelalH]

update the code in this repo https://github.com/fortanix/rust-sgx/blob/master/fortanix-vme/fortanix-vme-abi/src/lib.rs

NOTE: Use the alpha branch for this ticket

1. Check out the API and what could be improved
2. document the API

Action:

• A meeting with EDP team to explain the APIs and what needs to be done
• create new issues with outcome from this spike