Feat: Input Widgets in Notebook UI to control values of parameters

[stefanoperenzoni]

Let notebook users add widgets at the top of the Notebook to edit the value of parameters later used in query.

The idea would be extremely similar to Databricks widgets: https://docs.databricks.com/aws/en/notebooks/widgets

[quirkyllama]

Great idea- will look into exposing Malloy Parameters in the Notebook UI as widgets