multi-sig for governance commands

[jankun4]

Description

Adds multi-sig capabilities to governance init and update commands

link

Checklist

• Commit sequence broadly makes sense and commits have useful messages.
• The size limit of 400 LOC isn't needlessly exceeded
• The PR refers to a JIRA ticket (if one exists)
• New tests are added if needed and existing tests are updated.
• Relevant logging and metrics added
• Any changes are noted in the changelog.md for affected crate
• Self-reviewed the diff

[LGLO]

One general comment is that I really like how you deal with this additional layer of complexity. I was afraid that it would be much more invasive. Good job!