[Enhancement] Add a standardised encoding scheme for the SM(S)T and its proofs

[h5law]

Objective

This issue tracks the addition of a standard encoding scheme to serialise the SM(S)T itself and its proofs.

Origin Document

Encoding proofs is tracked in PR #21 however a more standardised approach to encoding not only the proofs but also the tree itself should be undertaken.

Goals

• Decide upon an encoding scheme (gob, json, protobuf, borsh)
• Implement the relevant helpers, functions and data types required to serialise and deserialise the tree and proofs deterministically

Deliverable

• Deterministic serialisation and deserialisation of proofs, and entire trees

Non-goals / Non-deliverables

• Change any underlying logic in the SM(S)T and proof mechanics

General issue deliverables

• Update any relevant README(s)
• Add or update any relevant or supporting mermaid diagrams

Testing Methodology

• Task specific tests or benchmarks: go test ...
• New tests or benchmarks: go test ...
• All tests: go test -v

---

Creator: @h5law
Co-Owners: @h5law

[h5law]

I think the encoding should focus on the proofs themselves. Not the entire SM(S)T. Closing this issue for now as we have basic proof serialisation via gob.