docs(data-integration): list all four sex codes

[akim1995]

Patient.extension:sex has a required binding to a four-code value set, and the page listed two:

184115007       Patient sex unknown (finding)
248152002       Female (finding)
248153007       Male (finding)
asked-declined  Asked But Declined

A required binding means a payer cannot substitute anything, so a partial list reads as the permitted set.

The link now points at the bound value set through the viewer instead of at the extension, so the codes are visible rather than requiring a click into the profile.

Adds a note that gender and sex are different elements with different bindings: gender is administrative gender as text, sex is a SNOMED CT code.