Archival Bag-info.txt file fails after #8592

[qqmyers]

What steps does it take to reproduce the issue?
The code in OREMap used to get the semantic mapping of a DatasetFieldType which was previously used only with parent fields is, after #8592, being used for the dsDescriptionValue child field when called to populate the bag-info.txt file in archival bags.

• What happens? log message about a null pointer in the BagGenerator class when creating an archival bag

**Which version of Dataverse are you using?**5.10.1 develop