PLT-273 Add slot to utxo query

[berewt]

We can now provide a upper slot when querying the utxos.

The route is added in marconi-sidechain: getUtxoFromAddress implementation is now aligned with the README documentation.

The request are of the form: {address : string, slotNo: number}, and slotNo is optional.

Pre-submit checklist:

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