chore(ssa_fuzzer): refactor ssa_fuzzer part 2/4

[defkit]

Description

Functions now can return references, arrays and slices

function_context.rs

• Now function returns Type instead of NumericType

fuzzer.rs

• get_return_value -> get_return_values, returns all return witnesses, not just one

instruction.rs

• input_types for functions are now Types, not numeric types. But fuzzer still fills all functions with numeric types (TODO in followups)

basic_tests.rs

• Added test checking that function can return array

Mutations

• Added mutations and generators for Type
• Removed random mutation from vector (from arbitrary bytes), because Type cannot implement Arbitrary.

runner.rs

• Now comparing all return witnesses, not just one

builder.rs

• Added insert_slice

Problem*

Resolves

Summary*

Additional Context

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: d2c1118	Previous: 387b9b2	Ratio
test_report_noir-lang_sha512_	16 s	13 s	1.23
test_report_zkpassport_noir-ecdsa_	3 s	2 s	1.50

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench

[Rumata888]

Remove or create an issue in the Noir repo and put the link here

[Rumata888]

Clean this up, please