fix: [stix2 import] Fixed MISP Object creation
fix: [stix2 import] Fixed MISP Object creation

- MISP Object creation function used for attack
  pattern & course of action objects, so they get
  the correct uuid
- MISP Object creation trying to parse the first
  seen & last seen values without raising issues
  when the object parsed does not have any

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