fix: readWrite transform drops unevaluatedProperties schemas with readOnly sibling
Add `unevaluatedProperties` to `childSchemaRelationships` as 'single' type
(same as `additionalProperties`) so the pruneSchemaByScope function
correctly recognizes it as a structural keyword and does not remove
schemas that use it alongside readOnly properties.
Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>