As a user, I can set different Custom Fields data for different Tests using Multipart

As a user, I can set different Custom Fields data for various Tests using Multipart Requests.

Example:
I want to submit Results for 10 Tests, and using the Info JSON (Test), I want to set a Description for the first 5 and a different Description for the remaining 5.
In the same example, I can set a different label for each Test.

This implementation should cover all Multipart Result submission (Robot Framework XML results, TestNG XML results, NUnit XML, etc.)