ElasticSearch deprecation notices

[pae-blue]

⚠️ Elasticsearch 8.x no longer supports specifying types in requests.

As of June 10, 2021, backends supports ElasticSearch 6.

Deprecation notices related to impending types removal:

• [ ] Specifying include_type_name in get index template requests is deprecated.
• [ ] Specifying types in search requests is deprecated.
• [ ] Specifying types in bulk requests is deprecated.

Other deprecation notices:

• [x] #616