Evaluate creating schema.json for SDDS

Problem/Motivation

Follow-up to:

📌 Decide if SDDS SDCs should include props from included components Needs review

We may want to have our own schema.json file to define our components.

See https://git.drupalcode.org/project/experience_builder/-/blob/0.x/schema....

Steps to reproduce

Proposed resolution

More research to inform decision and add schema if it makes sense.

Remaining tasks

See above.

User interface changes

API changes

Data model changes

JSON schema definitions.