Added association ref to committees

src/fiber_package/committee/committee.py

@@ -3,7 +3,8 @@ from pydantic import model_validator, UUID7
 from fiber_package.refs import (
     CommitteeEditionRef,
     CommitteeEditionRefList,
-    EntityRefList
+    EntityRefList,
+    AssociationRef
 )
 from fiber_package.base import FiberBaseModel
 
@@ -21,6 +22,8 @@ An edition is a definite group of members with functions and a timespan.
 class CommitteeModel(FiberBaseModel):
     collection_name: Literal["committee"] = "committee"
 
+    association: AssociationRef
+
     full_name_en: str
     full_name_nl: str
     description_en: str = ""
@@ -54,5 +57,5 @@ class CommitteeEditionModel(FiberBaseModel):
     def functions_to_members_only(self) -> Self:
         for uuid in self.functions:
             if uuid not in self.members:
-                raise ValueError("Cannot only assign functions to committee members")
+                raise ValueError("Can only assign functions to committee members")
         return self