Reconstruct nested values from function

[guipublic]

Related issue(s)

Resolves #492

Description

Summary of changes

Flatten data returned from a function is reconstructed into a value using the function return type.
This PR deprecate #537 I believe.

Test additions / changes

Regression test case added in 'struct' test case

Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt with default settings.
• I have linked this PR to the issue(s) that it resolves.
• I have reviewed the changes on GitHub, line by line.
• I have ensured all changes are covered in the description.

[guipublic]

N.B. I could not validate that this circuit is passing: https://github.com/vezenovm/aztec-circuits-noir/pull/5/files , as explained in issue #529,
because it uses dependencies (notes..) that are not provided.
@vezenovm, could you check that this PR works for this circuit?

[vezenovm]

Thanks for fixing up my PR @guipublic. This is a much cleaner way of handling it, I was looking only at create_function for generating the SSA func. I should have looked at the Expression::Call branch of codegen_expression to see what happens after create_function is called.

[jfecher]

Thanks 👍