[5pt] Add "notes" to library outputs for CatFIM

[RobHanna-NOAA]

Add a new "notes" field to the library outputs. For now, we can simply put the status when the message is about other missing stages. I think this would apply for both Flow and Stage.

Reasoning: If we see just one action layer, it makes people think it is an error and wonder where the other stages are at.

It very well might be worth adding "notes" to all sites and library objects for exactly this type of stuff, versus trying to use a string convention to show it is a warning like we currently do.