chore: order by catalog and schema name

Author: olavloite

google/cloud/sqlalchemy_spanner/sqlalchemy_spanner.py

@@ -1314,7 +1314,8 @@ def get_multi_pk_constraint(
                 AND tc.TABLE_NAME = t.TABLE_NAME
             WHERE {table_filter_query} {table_type_query}
             {schema_filter_query} tc.CONSTRAINT_TYPE = "PRIMARY KEY"
-            ORDER BY tc.table_name ASC, kcu.ordinal_position ASC
+            ORDER BY tc.table_catalog ASC, tc.table_schema ASC,
+                     tc.table_name ASC, kcu.ordinal_position ASC
         """.format(
             table_filter_query=table_filter_query,
             table_type_query=table_type_query,