Updates va_notify files and spec_files to be forward-compatible w/ new fields

[MarchandMD]

Summary

• This work is behind a feature toggle (flipper): YES/NO

Yes

• (Summarize the changes that have been made to the platform)

before this PR:
Files and spec files within modules/va_notify were using fields from the va_notify_notifications table that were backwards-compatible. Specifically, specs and objects were using callback field

After this PR:
Files and specs are now using the callback_klass field to be forward_compatible, without removing the backward-compatible fields from the schema (that'll be done in a subsequent PR)

• (If bug, how to reproduce)

N/A

• (What is the solution, why is this the solution?)

this is the solution because it will keep the arguments used to pass data to va_notify parallel with the data structure of the object being created (VANotify::Notification). Also, this separates the modification of files using a new table field from the updating of the table

• (Which team do you work for, does your team own the maintenance of this component?)

VA Notify

• (If introducing a flipper, what is the success criteria being targeted?)

N/A

Related issue(s)

1. https://github.com/orgs/department-of-veterans-affairs/projects/1415/views/1?pane=issue&itemId=85247150&issue=department-of-veterans-affairs%7Cvanotify-team%7C1411
2. Adds jsonb field to va_notify_notfications #19472
3. https://github.com/orgs/department-of-veterans-affairs/projects/1415/views/1?pane=issue&itemId=85247327&issue=department-of-veterans-affairs%7Cvanotify-team%7C1410
4. Uses new callback_metadata field in VANotify::Notification #19494
5. Adds new fields to va_notify_notifications #19502

Testing done

• New code is covered by unit tests
• Describe what the old behavior was prior to the change
• Describe the steps required to verify your changes are working as expected. Exclusively stating 'Specs run' is NOT acceptable as appropriate testing

bundle exec rspec modules/va_notify/spec/

Once the aforementioned PR is merged, updating the branch will result in passing tests

• If this work is behind a flipper:
  • Tests need to be written for both the flipper on and flipper off scenarios. Docs.
  • What is the testing plan for rolling out the feature?

Screenshots

Note: Optional

What areas of the site does it impact?

(Describe what parts of the site are impacted andifcode touched other areas)

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 (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

Requested Feedback

(OPTIONAL)What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?

[github-actions]

Backend-review-group approval confirmed.