Write governance items during init process

[aidan-kwon]

Proposed changes

Currently, governance items of the genesis block are stored when the node started.
This change makes the items to be stored during the init process.
Also, some governance-related code is refactored.

Types of changes

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• Bugfix
• New feature or enhancement
• Others

Checklist

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• I have read the CONTRIBUTING GUIDELINES doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules