Add the PHS aka the dbgap accession number to the Participant entity page

[denis-crsj]

This is the ID that is used when you apply for access on dbgap. This is also the id that the NIH puts on their managed KF page to indicate a study is released.

This value is stored as the external_id in Study, it needs to be added to the Participant entity page.

Label : dbGaP Accession Number
Location (Where to add this new field /value) --> ???

[denis-crsj]

Looks good. The field is there for dbGaP studies and does not show up if it's not. I'll also ask Bailey to validate just in case