Add "Unknown primary site" to primary_site controlled terminology

[hknahal]

Add the term Unknown primary site to the controlled terminology for primary_site. This corresponds to ICD-O code C80.9. This will accommodate the POG-CA program where they have some donors with unknown primary sites who have metastatic cancer.

Use Cases:

• if a person has a carcinoma that has spread to the lung and the site of origin is unknown, the appropriate code is C80.9 (unknown primary site (Reference: Morphology - SEER Training and NCI)
• If no site is indicated for lymphoma and it is suspected to be extranodal, then code C80.9 (unknown primary site) (Reference: ICD-O manual page 15)

[puneet-oicr]

@b-f-chan Needs someone assigned for testing.

[hknahal]

Released in Dictionary version 1.16