Add explicit uuid support to forms schema to enable deterministic create/upate behavior across systems

[makombe]

This PR introduces a required uuid property in the form JSON schema to support deterministic form creation and updates.

Previously, forms could be created with randomly generated UUIDs, which caused inconsistencies across distributed systems and made it difficult to reliably identify and update the same form across different implementations.

With this change:

• If a form with the provided uuid already exists, the system will update the existing form.
• If no form exists with the provided uuid, the system will create a new form using that exact uuid.