user_group: Move UserGroupMembershipDetails from lib/streams.py.

zerver/lib/streams.py

@@ -25,6 +25,7 @@ from zerver.lib.string_validation import check_stream_name
 from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.types import AnonymousSettingGroupDict, APIStreamDict
 from zerver.lib.user_groups import (
+    UserGroupMembershipDetails,
     get_recursive_group_members,
     get_recursive_membership_groups,
     get_role_based_system_groups_dict,
@@ -549,11 +550,6 @@ def check_for_exactly_one_stream_arg(stream_id: int | None, stream: str | None)
         raise IncompatibleParametersError(["stream_id", "stream"])
 
 
-@dataclass
-class UserGroupMembershipDetails:
-    user_recursive_group_ids: set[int] | None
-
-
 def user_has_content_access(
     user_profile: UserProfile,
     stream: Stream,