Remove legacy git-message api

[rkotze]

Remove legacy git-message API and replace it with git-mob-core API.

You should still be able to printout to the console and write to the template message file. Not change to functionality.

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• All tests and linting (npm run checks) has passed locally and any fixes were made for failures
• I kept my pull requests small so it can be reviewed easier

Pull request type

Please check the type of change your PR introduces:

• Refactoring (no functional changes, no api changes)

Does this introduce a breaking change?

• Yes
• No

Other information