ZSQLCatalog: support dict.keys()/items() as search values

constructs like `portal_catalog(title=d.keys())` were allowed on
python2, we can allow them on python3 as well.
5 jobs for feat/catalog-dict-views in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner2

02:42:13

passed ERP5.UnitTest-TestRunner2

03:49:39

passed ERP5.CodingStyleTest-TestRunner2

01:28:54

passed ERP5.CodingStyleTest-TestRunner2

01:02:35

passed ERP5.UnitTest-TestRunner2

02:00:32