[later phase] [PP-1] Create/edit UI for `PropShapeInput` config entity type

Overview

#3461499: Support complex SDC prop shapes: introduce (Storable)PropShape to compute field type storage settings added the PropShapeInput config entity type. It includes only a listing.

It should become possible to create/edit these config entities using a UI. That UI can largely be extracted from the existing \Drupal\experience_builder\Form\ComponentEditForm.

Proposed resolution

Add such a UI.

User interface changes

TBD