feat: Parse the DefinitionList at source

[GordonSmith]

Ensure there are always "some" values for TimeLocalExecute

Checklist:

• The commit message is properly formatted and free of typos.
  • The commit message title makes sense in a changelog, by itself.
  • The commit message includes a "fixes" reference if appropriate.
  • The commit is signed.
• The change has been fully tested:
  • I have viewed all related gallery items
  • I have viewed all related dermatology items
• There are no similar instances of the same problem that should be addressed
  • I have addressed them here
  • I have raised new issues to address them separately

Testing:

[jeclrsg]

@GordonSmith maybe a small problem in that regex? Not sure, tbh. I think it works either way.

[GordonSmith]

@jeclrsg converting to draft as there are some more changes that should go in here...