CP-ITI-1297: Support data from segments GSP and GSR in XDS DocumentEntry.sourcePatientInfo

[unixoid]

CP: https://docs.google.com/document/d/1ga7W8O2bN_A4Rxe6esEp73x9XhyjnbD6/edit

New requirements in ITI TF-3:4.2.3.2.23:

The sourcePatientInfo attribute MAY optionally include gender identity, pronouns, and recorded gender and sex for the patient. If represented, actors SHALL encode gender identity and pronouns using the GSP (Gender, Sex, and Pronouns) segment as defined in HL7 v2.9.1.

I don't think that we need this for IPF 5.2 (or ever), but create this issue for the sake of completeness.