Use ref instead of owned Block in validation

[MitchTurner]

#1882

Checklist

• Breaking changes are clearly marked as such in the PR description and changelog
• New behavior is reflected in tests
• The specification matches the implemented behavior (link update PR if changes are needed)

Before requesting review

• I have reviewed the code myself
• I have created follow-up issues caused by this PR and linked them here

After merging, notify other teams

[Add or remove entries as needed]

• Rust SDK
• Sway compiler
• Platform documentation (for out-of-organization contributors, the person merging the PR will do this)
• Someone else?

[xgreenx]

Yeah, you can have two types. One for serialization on our side and one for deserialization on the WASM side. On our side you can pass reference

[MitchTurner]

Maybe instead of serializing ReturnType::V1(result) in extern "C" fn execute, we serialize some Result<ReturnType, Error>?

That way we don't need the ReturnType variant to return an Err.

i.e. We can do something like:

enum ReturnType {
    V1(V1ReturnType)
}

enum V1ReturnType {
    Execute(ExecutionResult),
    Validate(ValidationResult),
}

[xgreenx]

We want to return an ExecutorResult because we may change the error type later. We could add V2 that returns a validation result and name it Validation instead of V2=)

But I don't see any problems in returning ExecutionResult with a block type since we don't consume block, and it doesn't hurt the performance.

[xgreenx]

Actually, it affects performance. We need to serialize and deserialize the block on the upgradeable executor side, so maybe we should add a new return variant. But let’s do it in a separate PR, we need to add an integration test for it to be sure that we did everything correct=)

[MitchTurner]

#1887