chore(nargo): add test for reading/writing inputs to fs

[TomAFrench]

Related issue(s)

#995

Description

Summary of changes

This PR adds a quick test that if we write an input map and return value to a file then we will recover the same values when we read from that file again.

As we're now testing equality outside of noirc_abi we need to always derive PartialEq.

Dependency additions / changes

Test additions / changes

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.

Documentation needs

• This PR requires documentation updates when merged.

Additional context

[phated]

I like tests 🎉