Enable prompt creator to optionally submit UI Schema dictating prompt formatting

[dfederschmidt]

Currently, there is a sensible set of default widgets being rendered. In some cases though, there may be the need to customize appearance. The react library used to generate the forms has this capability, but it is not yet exposed to the prompt creator. Idea would be to add a new field to a Prompt entity that would provide the UI Schema.

Documentation: https://react-jsonschema-form.readthedocs.io/en/latest/api-reference/uiSchema/