[Governance] Upgrade playbook and downstream investigation

[Olshansk]

Objective

Write the playbook on how we'll handle on-chain governance updates.

Origin Document

• Cosmos upgrade module: https://docs.cosmos.network/v0.50/build/modules/upgrade
• Morse RC-0.11 Release Plan: https://buildwithgrove.notion.site/RC-0-11-0-Release-Plan-6b33e7b7634f458796b1c3f0a3a2a994?pvs=4
• Related to #622 but solely for on-chain purposes

Goals

• Research and understand the tools available in the Cosmos SDK for governance upgrades (i.e. x/upgrade)
• Identify missing gaps or differences between how we'll handle governance upgrades
• Collaborate with the team at Informal Systems (CometBFT) or Binary Builders (Cosmos SDK) if need be

Deliverables

• [ ] Manage a real consensus-breaking governance upgrade on TestNet
• [ ] A copy-paste template + playbook + instructionsfor every governance upgrade
• [ ] Answer the following questions:
  • [ ] How do we handle consensus-breaking changes?
  • [ ] How do we increase the block size like in Morse? (e.g. increase the block size)
  • [ ] How do we activate a new feature at a specific height? (i.e. boolean feature switch)
  • [ ] Document protocol updates and governance upgrades

Non-goals / Non-deliverables

• Implementing new features (e.g. features switches) if the need arises
• Achieving complete parity with how Morse work

General deliverables

• [ ] Comments: Add/update TODOs and comments alongside the source code so it is easier to follow.
• [ ] Testing: Add new tests (unit and/or E2E) to the test suite.
• [ ] Makefile: Add new targets to the Makefile to make the new functionality easier to use.
• [ ] Documentation: Update architectural or development READMEs; use mermaid diagrams where appropriate.

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Creator: @Olshansk Co-Owners: @okdas