[WIP][Utility] Foundational bugs, tests, code clean up, and improvements (3/3)

[jessicadaugherty]

Objective

Partial refactor, cleanup, and code improvement of the utility module to set a foundation for M3.

Origin Document

Follow-up work to part 2/3 #504. Address the items not refactored in #504 as noted on PR #550.

When work on #443 started, while also looking at #325, it became evident that the logic in the utility module is hard to follow and understand while also being filled with minor hard-to-find bugs.

Goals

• Unblock development: Create a foundation on which we design utility protocols and implement new features
• Reduce cognitive overhead: Improve code readability and navigation for both internal and external contributors
• Enable onboarding other engineers: Clarify both source code and tests through comment and source code improvements

Deliverable

• A list of follow up tasks / tickets / improvements that are not essential to unblock M3 work but need to be tended to
• A PR that updates the portions of the utility module noted above
• Documentation & explanation of the changes that were made and next steps
• Reviewing and updating the following files where appropriate:
  utility
  • ├── block.go
  • ├── block_test.go
  • ├── doc
  • │   ├── PROTOCOL_RELAY.md
  • │   ├── PROTOCOL_SESSION.md
  • │   └── README.md
  • ├── gov.go
  • ├── gov_test.go
  • ├── message_test.go
  • ├── module_test.go
  • ├── service
  • │   └── service.go
  • ├── transaction.go
  • ├── transaction_test.go
  • ├── tx_message_handler.go
  • ├── types
  • │   ├── constants.go
  • │   ├── error.go
  • │   ├── gov.go

Non-goals / Non-deliverables

• Updating the entire module in a single PR (PR would be too large)
• Adding new features to the utility module
• Increasing/improving the test coverage to the po

General issue deliverables

• Update the appropriate CHANGELOG(s)
• Update any relevant local/global README(s)
• Update relevant source code tree explanations
• Add or update any relevant or supporting mermaid diagrams

Testing Methodology

• All tests: make test_all
• LocalNet: verify a LocalNet is still functioning correctly by following the instructions at docs/development/README.md

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Creator: @jessicadaugherty
Co-owner: @Olshansk

[jessicadaugherty]

@Olshansk ready for review 👍