Add warning when turning on production decomposition if production has custom code

If an interoperability production has custom code like methods in the class definition, they currently cannot be source controlled if production decomposition is enabled. We should add a warning on the settings page and in the Configure prompt if this is the case. Some sample warning text with advice would be:

Custom code detected in Production class. Custom code (methods, properties, etc.) must be moved to a separate class to be source controlled if production decomposition is enabled.

Locate the production-decomposition settings page and Configure prompt entry points; first trace how an interoperability production is inspected for custom code. Done means the warning appears in both locations when custom code is present and includes guidance to move that code to a separate class.

Scritto dal modello di indicizzazione a partire dal testo della issue.