Fix(543): Initialize data undefined in transformJSONSchema

[bjmccotter7192]

Description

Updating transformJSONSchema to set values to undefined.

This work will help us strip and clean the data in the transformForSubmit function.

NOTE: Updated burial example form with flattened values for conditional routes

Original issue(s)

department-of-veterans-affairs/va-forms-system-core#543

Testing done

• [ ] All Unit Tests Pass

Definition of done

• [ ] Package.json version has been updated to match Github release tag
• [ ] Documentation has been updated, if applicable
• [ ] A link to the original github issue has been provided
• [ ] No sensitive information (i.e. PII/credentials/internal URLs etc.) is captured in logging, hardcoded, or specs

[va-vsp-bot]

:tada: This PR is included in version 1.4.2 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: