For issues #2670 and #2706.

Note: BitShares Mekong 6.1 can work with ElasticSearch version 8 already, except that

• need to configure ES with xpack.security.http.ssl.enabled=false, and
• the history_api::get_account_history API doesn't work, and
• the es_test unit tests will fail.

This PR fixes the API and the test cases mentioned above.

• Fix for ES 8 key_not_found_exception: {"key":"count"}
  

  bitshares-core/tests/elasticsearch/main.cpp

  Line 84 in bd440cf

  total = j["count"].as_string();

  
  Cause: cannot specify types in ES 8 (see Fix for ES7 : Specifying types is deprecated. #1997).
  • Type _doc is used in the elasticsearch_plugin::get_account_history() function, which is used in an API and related unit tests. I think nobody is using it in production.
  • Type _doc is used in the elasticsearch_plugin::get_operation_by_id() function, which is unused (added in elasticsearch history api #1682 #1725 with context).
  • Type _doc is used multiple times in es_test. Note that _doc is needed for the GET API, but should not be used with the SEARCH API or the COUNT API.
• Fix for ES 8 Wildcard expressions or all indices are not allowed when trying to delete all indices for cleanup in unit tests.
  Cause: different default behavior between ES 7 and ES 8.
  • ES 7 (https://www.elastic.co/guide/en/elasticsearch/reference/7.17/indices-delete-index.html):

    To delete all indices, use _all or * . To disallow the deletion of indices with _all or wildcard expressions, set the action.destructive_requires_name cluster setting to true.

  • ES 8 (https://www.elastic.co/guide/en/elasticsearch/reference/8.5/indices-delete-index.html):

    By default, this parameter does not support wildcards (*) or _all. To use wildcards or _all, set the action.destructive_requires_name cluster setting to false.