groonga: Generate better queries for drilldown
Add tests for search requests converted from drilldown
test: Update testing queries
test: Fix syntax error
groonga: Extract method to convert main select result
groonga: Convert drilldown results
test: Add missing output element to expected results
test: Add tests for drilldown
groonga: Merge drilldown results
test: Fix expected convert result for drilldown results
test: Fix expected convert results
groonga: Convert select results correctly
groonga: Convert "sortby" option
test: Add tests for conversion of "sortby" option