Add foreign function for recursion

[kevaundray]

Problem

Once recurson is added to acvm we would want a way to support this feature for users.

Proposed solution

As usual, we can add a foreign function which will handle this, the proposed function signature is as follows:

#[foreign(recursion)]
fn verify_proof(proof : [u8], verification_key : [u8], public_inputs : [u8]) -> bool;

Alternatives considered

No response

Additional context

No response

Submission Checklist

• Once I hit submit, I will assign this issue to the Project Board with the appropriate tags.

[vezenovm]

As per the discussion in noir-lang/acvm#198 the function signature will be changed to take in an input aggregation object and an output aggregation object:

#[foreign(verify_proof)]
fn verify_proof(_verification_key : [Field], _proof : [Field], _public_input : Field, _input_aggregation_object : [Field]) -> [Field] {}

[Savio-Sou]

Closed by #1594

Keyword in stdlib: https://github.com/noir-lang/noir/blob/master/noir_stdlib/src/lib.nr#L31-L32