Function used in mission creation.
Objective: The player has to escort a single NPC or a group along a path. This path can be set by a spline, or the escorted group can follow the player during his travel. This objective is usually controlled by instructions from the AIS:
name: Objective name, only used by the mission designer.
group_to_escort: Tag name of the group to be escorted.
hide_obj (Boolean): Prevent the step to be displayed in the mission log.
overload_objective: Allow to set a specific a description of the mission. See text guidelines for the formatting requirements.
roleplay_objective (Optional): Allow to add a description to the step.
save_all (Boolean): If checked, the objective fails when a member of the escorted group dies.