As a user, I want to know the unit or nilReason for an attribute.

[jordanpadams]

🧑‍🔬 User Persona(s)

Data User

💪 Motivation

...so that I can properly utilize the value being returned by the API.

📖 Additional Details

Currently, the registry and API only care about the XML values, but we also need to include the attribute unit and nilReason. These are both specified as XML attributes in the label.

⚖️ Acceptance Criteria

Given
When I perform
Then I expect

⚙️ Engineering Details

We need to figure out

• how or if this is returned by the API
• should this be a specific endpoint that provides units of measure for particular product attributes
• should we just include this in the pds4+json/pds4+xml responses?