add passage attribute to item and bundles generation method for solver run

app/models/item.py

@@ -1,5 +1,5 @@
 from pydantic import BaseModel
-from typing import List
+from typing import List, Optional
 
 from models.attribute import Attribute
 
@@ -8,6 +8,7 @@ from lib.irt.item_information_function import ItemInformationFunction
 
 class Item(BaseModel):
   id: int
+  passage: Optional[int]
   attributes: List[Attribute]
   b_param: float = 0.00
 
@@ -27,4 +28,4 @@ class Item(BaseModel):
     for attribute in self.attributes:
       if attribute.id == ref_attribute.id and attribute.value == ref_attribute.value:
         return True
-    return False
+    return False