Hello Matt,
I see that you want to have a State-Based versioning tool for Google Cloud SQL.
From the link
here, there is a description:
State Based Approach
In State based database delivery, you will need to store a snapshot of the current state of the database in your source control. Every table, stored procedure, view, trigger will be saved as separate sql files which will be the real representation of the state of your database objects.
When you want to modify the database schema or reference data, all you need to do is explicitly mention the expected database state. The Compare Tool does all the magic and generates the difference script which then gets executed against the database.
There is no equivalent versioning for Cloud SQL as you have discovered. For tool recommendation, I would provide you with a
link for the benefit of the community that has links to versioning products, some not open source, some free.
I hope this helps.