Implement upgradable governance

[jstolarek]

We need to implement an upgradable governance mechanism as outlined in SIP-16.

Requirements

Repeated from the SIP:

• A default securing mechanism is a N-of-M multi sig where the partner chain developer is responsible for defining the values of N, M and the wallets in question
• This should be configurable to allow arbitrary logic
  • The partner chain developer may have a DAO in place
  • They may be happy with a “proof of authority” solution with a manager NFT
• This should be upgradeable (in case the partner chain developer eventually gets a governance mechanism to replace the default, or makes an upgrade to a previous mechanism)
• Upgrading this mechanism should require the prover to show they can meet at least the current security threshold

Remaining implementation outline

• Add updatable governance to transactions that require it #55
• Parameterize governance version in the redeemer #56
• Use modular governance to manage the versioning system #57
• Implement user interface for multi-signature governance #60

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IOG Jira: https://input-output.atlassian.net/browse/ETCM-7669