Gocamgen changes - model taxon, provided_by, annot prop handling

[dustine32]

• Adds model-level taxon ID - https://github.com/geneontology/gocamgen/issues/80
• Adds model- and evidence-level provided_by (aka Assigned_by)
• Adds date and contributor to ALL annotation individuals - https://github.com/geneontology/gocamgen/issues/86
• Updates handling of new properties DS from https://github.com/biolink/ontobio/issues/513

@dougli1sqrd Feel free to get angry and spit all over my GroupsHelper code here. It was my attempt at converting GAF/GPAD Assigned_by values (e.g. MGI, WB) to the URI (e.g. http://informatics.jax.org) for OWL without either hard-coding the table or adding a groups_yaml arg to the gpad2gocams cmd. Open to suggestions!