[DBX-75526.1] add aasm_state column to form526 subs

[SamStuckey]

Top level documentation for this improvement is here

Summary

• per the documentation, the Form 526 State machine is being broken into 3 migrations. This is the first which adds the requisite column to our form526 submission DB table.
• A subsequent PR will add the default state value
• A subsequent PR will add the model and implementation logic

Related issue(s)

• Ticket
• Documentation

Testing done

• There is nothing to test, as this is bare bones, core rails functionality

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog or Grafana (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

[ryan-mcneil]

[SamStuckey]

Rebased to remove DB artifact, new review required

[NB28VT]

LGTM 🚢

[freeheeling]

approved

[ryan-mcneil]

👍