EZP-23129: update fixture for changed behaviour
EZP-23129: add tests
EZP-23129: changed: always sort null last
EZP-23129: fixed: use sortable field
EZP-23129: add reverse sort tests
EZP-23129: add missing Elasticsearch fixtures
EZP-23129: updated fixtures: null always sorted last
Merge pull request #1101 from ezsystems/fix-EZP-23129-sort-filtering

Fix EZP-23129: sorting by field filters the result set