Following the discussion on T3034, we decided to replace SWHID with
two or three classes:
- QualifiedSWHID to replace the existing SWHID (standard types + qualifiers)
- CoreSWHID, for "core SWHID" only (standard types + no qualifiers)
- ExtendedSWHID for internal use in Software Heritage (extra types + no qualifiers)
This commit adds the second one