fix: replace message related to json into JSON type from JSONB

[dadamu]

Description

This PR intends to fix the issue that message JSON may includes invalid Unicode sequence \u0000, it would cause the error when saving transactions and messages into Database.

Reference:
Invalid unicode sequence on PostgreSQL
Jackal transaction including invalid unicode sequence

Related issue: forbole/juno#114

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Author Checklist

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I have...

• included the correct type prefix in the PR title
• added ! to the type prefix if API or client breaking change
• targeted the correct branch
• provided a link to the relevant issue or specification
• added a changelog entry to CHANGELOG.md
• included comments for documenting Go code
• updated the relevant documentation or specification
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

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I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage
• manually tested (if applicable)