Gender and sex terminology

[buske]

@liberaliscomputing brought this up in https://github.com/ga4gh-cp/pedigree/pull/6/files#r568054506

We discussed further on our 2021-02-04 call: meeting minutes

It seems like the consensus is that the default within genetics is to default to recording and visualizing the pedigree based on the individual's (presumed) sex at birth for the purposes of pedigree structure and primary node visualization. The sex field will be required.

The gender field will remain optional, and represents an individual's gender identity, especially in cases where it differs from the biological sex at birth. This will then allow for adoption of upcoming trans-inclusive pedigree visualization standards: J Genet Cous 2019.

We are looking for input on the above proposal, and on what terminologies should be used for the sex and gender coding.