wip: [stix2 import] Updated external observable mapping: files with artifact & directory references
wip: [stix2 import] Updated external observable mapping: files with artifact & directory references

- The parsing logic is already there since files
  with artifact references and files with directory
  references are supported. We just updated here
  the mapping dictionary

SteveClement/MISP,SteveClement/MISP,MISP/MISP,MISP/MISP,MISP/MISP,SteveClement/MISP,MISP/MISP,SteveClement/MISP,SteveClement/MISP,MISP/MISP