Chain of Custody: Improve Schema References in Code Snippets

[harleytrustprovenance]

Impacted sections

• https://uncefact.github.io/spec-untp/docs/specification/ChainOfCustody

Issue Description

Currently, the schema references in the code snippets are too coarse and poorly defined. Instead of general schema references, the references should be more granular - aligning with specific criteria, regulations, or standards, similar to the existing assessment model in the DCC.

Tasks:

• Review all code snippets referencing schema
• Refactor references to align with the DCC specification.
• Document examples where appropriate to improve clarity.

Related to, and dependent on, PR #253 .