This task is to create the minimal tooling for consumers to customize the generic form generated by the extension. Initially through a separate file that represents the "UI schema". This should facilitate evaluating the suitability of using the concept broadly for form customization. The lack of this abstraction has lead to mix the definition of UI elements with the definition of data in their schemas. An example of this is the control property in MediaWikiDefinitions which binds a schema definition to a specific control.

The proposal needs to be backwards compatible with existing providers that do not provide a UI schema and should be easy to adopt incrementally. Ideally the control property would no longer live in the data schema, however that is not the main goal of this task. The goal is to allow an initial customization into a field (mediawki or not) from a different source than the data schema, the "UI schema". This should serve as example for further customization options, including overriding the control provided by default by the extension.

Acceptance criteria

• Consumers can configure a generic control customization, eg: a filter for the PageTitleControl
• The customization is defined outside of the json data schema
• An example of usage of a UI schema is provided