[Proof] Update post-scaffolding for the Proof type

[Olshansk]

Objective

• Prepare the codebase for [Protocol] MVP implementation off the on-chain SubmitProof message handling #141

Origin Document

Goals

• Prepare the codebase to implement MVP logic for SubmitProof
• Put basic validation, plumbing and other business logic in place to make the core business logic easier
• Do the "busy work" so we can focus on the interesting and important work of Proof submission

Deliverables

• Similar to how [Supplier] Basic validation logic for CreateClaim #148 and [Supplier] Updating the scaffolded Claim type #151 were implemented for the Claim type after [Supplier] Scaffold the Claim type #149 was merged, do the same thing for Proofs
• Increase the test coverage for Claim along the way if any missing gaps were identified

Non-goals / Non-deliverables

• Implement the core business logic for Proffs
• Make any business logic for Claims
• Modify any off-chain business logic.

General deliverables

• Comments: Add/update TODOs and comments alongside the source code so it is easier to follow.
• Testing: Add new tests (unit and/or E2E) to the test suite.
• Makefile: Add new targets to the Makefile to make the new functionality easier to use.
• Documentation: Update architectural or development READMEs; use mermaid diagrams where appropriate.

---

Creator: @Olshansk
Co-Owners: @bryanchriswhite