Support OpenSearch 2 by removing deprecated mapping types

[mauricebolhuis]

As part of OpenSearch 2, support for mapping types is removed. As a result:

• the type parameter is removed from rest end-points.
• the include_type_name parameter is removed from API requests.

This pull request also removes these parameters from opensearch-rails.
See https://www.elastic.co/guide/en/elasticsearch/reference/7.17/removal-of-types.html for more info on mapping types and why they are being removed.

See also:

• https://github.com/opensearch-project/opensearch-build/blob/main/release-notes/opensearch-release-notes-2.0.0.md
• Remove mapping types opensearch-project/cross-cluster-replication#318
• Removes usage of mapping types opensearch-project/job-scheduler#155
• https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html

[martijnbolhuis]

Ziet er goed uit. Ik heb nog één dingetje gevonden.