Fix empty results when language is set in query

Thank you, patch #2 solved our same issue.

@pguillard, @szato, in 📌 Investigate search_api_opensearch as base for elasticsearch_connector Fixed , we changed how search queries are built. Unfortunately, we don't yet have a migration path from the 8.x-7.x branch of the project (but we've filed 📌 Upgrade path from 8.x-7.x branch Active to capture that work).

However, we would greatly appreciate it if you were able to try out the latest 8.0.x-dev release → and see if searching when the language is set in the query works correctly now. If it does not, may we trouble you to change this issue's "Status" back to "Needs work"?

(I'm cleaning up issues in the 8.0.x-dev branch as part of a big review of open issues for 🌱 Plan for 8.0.0-alpha release Active : thank you for your patience with me!)