feat(api): Add preview endpoint

[tatarco]

What changed? Why was the change needed?

We need a quick stateless preview endpoint in order to have a single point or rendering for all workflows type.
what was done?

1. full flow controller -> hydration -> validation -> render for the preview endpoint.
2. move new V2 DTO's to a shared-internal package allowing the creation of clients for the FE to use as well as out E2E

https://www.loom.com/share/a3041ae59a9843bf98bb98829ca12a56?sid=6ac0f038-6c1e-4d5c-81c1-2761b7df5977

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