[later phase] PropShapes' JSON schema must match exactly with FieldType's storage format — what if you want to use another FieldType + Adapter?

Thoughts, @lauriii?

📌 Support complex SDC prop shapes: introduce (Storable)PropShape to compute field type storage settings Fixed has landed since.

And more recently, 📌 Clarify the "shape matching" bits: namespaces, `CODEOWNERS` and as issue queue component Fixed landed and brought much more clarity.

So, massively simplifying/clarifying this title.

📌 [PP-1] Add support for matching SDC prop shape: {type: string, enum: …} Postponed should be implemented before this, but that doesn't stop designs for the adapter UX — the design for both probably should happen simultaneously, i.e. should be part of the very same design.