documents: fix libraries aggregations

* Limits the number of terms in the libraries aggregations facets from
10 to 50.

Co-Authored-by: Johnny Mariéthoz <Johnny.Mariethoz@rero.ch>

rero_ils/modules/libraries/api.py

@@ -64,9 +64,8 @@ def get_libraries_by_organisation_pid(self, org_pid, fields=None):
         query = self.filter('term', organisation__pid=org_pid)
         if fields:
             query = query.source(includes=fields)
-        response = query.execute()
-        for hit in response.hits.hits:
-            yield hit._source
+        for result in query.scan():
+            yield result
 
 
 class Library(IlsRecord):