Returns the associated files of a marked-content sequence, from the property list of its /AF tag.
public IReadOnlyList<PdfFileSpecification> ReadMarkedContentAssociatedFiles(CosObject? properties)
The property list operand of /AF ... BDC, resolved from the Properties resource, or a reference to it.
ISO 32000-2 §14.13.5 and errata Table 409a: a property list dictionary whose MCAF array lists the files (each shall
have AFRelationship), or, as in the original text's Example 2, a resource that is the array itself. Both are accepted.