PLT-749: Added rountrip ToJSON/FromJSON and ToField/FromField property tests

[koslambrou]

Added rountrip ToJSON/FromJSON and ToField/FromField property testsy tests for all orphan instances in marconi-chain-index, and for StorableResult datatype in the UTXO indexer

Pre-submit checklist:

• Branch
  • [ ] Tests are provided (if possible)
  • [ ] Commit sequence broadly makes sense
  • [ ] Key commits have useful messages
  • [ ] Formatting, PNG optimization, etc. are updated
  • [ ] Important changes are reflected in changelog.d of the affected packages
• PR
  • [ ] Self-reviewed the diff
  • [ ] Useful pull request description
  • [ ] Reference the ADR in the PR and reference the PR in the ADR (if revelant)
  • [ ] Reviewer requested

[koslambrou]

@kayvank Normally, this PR would solve the datum issue in the PR #947