Issue #9539: Add missing entries for IPTC Digital Source Type

This patch attempts to resolve Issue #9539 (closed). On June 14 2022, new metadata tags were added to the IPTC Extension Digital Source Type field to better describe "synthetic media". I added all the ones listed to the dropdown.

@Wormnest, if/when you have time, is there any issues with adding these extra values? It seems to save and load properly, but I'm not as familiar with metadata saving/loading.