simplify unused objectives display and tie-break

src/warchron/model/war.py

@@ -175,6 +175,14 @@ class War:
     def get_all_objectives(self) -> List[Objective]:
         return list(self.objectives.values())
 
+    def get_objectives_used_as_maj_or_min(self) -> List[Objective]:
+        obj_ids: set[str] = set()
+        for camp in self.campaigns:
+            obj_ids.update(camp.get_objectives_used_as_maj_or_min())
+        return [
+            self.objectives[obj_id] for obj_id in obj_ids if obj_id in self.objectives
+        ]
+
     def get_objective_name(self, objective_id: str | None) -> str:
         if objective_id is None:
             return ""