Cannot search by index type anymore

[sebbalex]

Description

Since Elasticsearch 7.x is not possible to search by index type mostly due to this. We should then treat _type field not as a special field.

Checklist

• [X] I followed the indications in CONTRIBUTING.md
• [ ] The documentation related to the proposed change has been updated accordingly (also comments in code).
• [ ] Have you written new tests for your core changes, as applicable?
• [X] Have you successfully ran tests with your changes locally?
• [ ] Ready for review! :rocket:

Fixes

Fixes #