Handle and log errors when ingesting bioschemas content

[fbacall]

Summary of changes

• Catches and logs exceptions that occur when scraping Bioschemas sources.
• Fixes awkward formatting of error messages when markdown is rendered.

Motivation and context

A user was trying to test a Bioschemas source, and a single page with a JSON error caused the entire ingestion to fail with a generic error message.

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.