Ensure only "safe" types are written to the source test result YAML.
Motivation and context
Bioschemas sources with mentions (parsed as external resources) were breaking the source testing page.
Checklist
[x] I have read and followed the CONTRIBUTING guide.
[x] I confirm that I have the authority necessary to make this contribution on behalf of its copyright owner and agree
to license it to the TeSS codebase under the
BSD license.
Summary of changes
Motivation and context
Bioschemas sources with
mentions
(parsed as external resources) were breaking the source testing page.Checklist