/gtin should expect URLs (URIs), as promoted by GS1 #3156
Description
We do not currently define /gtin as expecting URLs (URIs).
The most recent direction of the GTIN work at GS1 is all about enabling this, and the /gtin definition at Schema.org in its textual form already anticipates URI/URL values.
The lack of a declaration that the /gtin property has /rangeIncludes /URL is pure oversight.
Talking with @philarcher it may also be useful to include the regex for extracting textual GTINs from full URL/URI.