Add Create-a-Class Functionality

[EthanC]

• https://my.callofduty.com/api/papi-client/loadouts/v4/title/bo4/items/mode/mp/en
• https://my.callofduty.com/api/papi-client/loadouts/v3/title/bo4/platform/psn/gamer/ImMotive__/mode/mp/slot/0
  {"primaryWeapon":{"id":"smg_standard_t8","optic":null,"variant":{"id":null},"attachments":[{"id":null},{"id":null},{"id":null},{"id":null},{"id":null}],"operatorMod":null,"headshots":0,"camoEquipped":false},"secondaryWeapon":{"id":"pistol_standard_t8","optic":null,"variant":{"id":null},"attachments":[{"id":null},{"id":null},{"id":null},{"id":null},{"id":null}],"operatorMod":null,"headshots":0,"camoEquipped":false},"wildcards":[{"id":null},{"id":null},{"id":null}],"perks":[{"id":"talent_engineer"},{"id":"talent_lightweight"},{"id":"talent_ghost"},{"id":null},{"id":null},{"id":null}],"equipment":{"id":"default_specialist_equipment","count":1},"gear":{"id":"gear_medicalinjectiongun"},"customClassName":"","unlocked":true,"isChanged":true}