user_group: Show subgroups in popover.

Previously, all members of the group, including members of
recursive groups, were shown in the the popover. Now only
direct members are shown along with the direct subgroups
of the group.

Fixes #32088.

web/src/user_groups.ts

@@ -335,6 +335,17 @@ export function get_potential_subgroups(target_user_group_id: number): UserGroup
     });
 }
 
+export function get_direct_subgroups_of_group(target_user_group: UserGroup): UserGroup[] {
+    const direct_subgroups = [];
+    const subgroup_ids = target_user_group.direct_subgroup_ids;
+    for (const subgroup_id of subgroup_ids) {
+        const subgroup = user_group_by_id_dict.get(subgroup_id);
+        assert(subgroup !== undefined);
+        direct_subgroups.push(subgroup);
+    }
+    return direct_subgroups;
+}
+
 export function is_user_in_group(
     user_group_id: number,
     user_id: number,