An option to display search for MorphTo field (in edit/create mode)

[alies-dev]

For the \Laravel\Nova\Fields\MorphTo it will be nice to have an option to disable search field and only display "create" button

Why: in some cases, there is no sense to create child resource first and then parent: they always created in a pair. My case: LMS has quizzes that have typed quizzes (e.g. open-ended question, multiple choice question, etc)