Remove mapping types

[dreamer-89]

As part of v2.0 release, mapping types are getting removed from OpenSearch engine. Below are the changes in the opensearch-engine.

• Removal of type from rest end-points
• Removal of include_type_name parameter from API requests.

As part of this issue, please verify if type removal change on OpenSearch engine impacts this repository. If yes, then please remove the type references/usage from this plugin.

Top level changes are captured in gist below:
https://gist.github.com/dreamer-89/d76eaf639171e8ab32fa7f8b9d6c93d3

For more detailed changes, please check meta issue below:
Related: OpenSearch-engine meta issue

[ohltyler]

After a quick search in the plugin, I see mapping types are used in a few places to init system indices, using mapping() method (example). Note this method is now @deprecated in main branch of OpenSearch, which is tracking 2.0.0 (ref)

Checked a few other repos, and I see similar uses:
alerting plugin
index-management plugin

[dreamer-89]

@ohltyler: Thank you for the update here.
Is there a way we can find out all places which are impacted ? Will running integration tests (against OpenSearch main) help in identifying all breaking changes ?

[ohltyler]

As discussed separately offline, the campaign for removing mapping types at the API-level in core OpenSearch is done, which I believe is the only way this is used in this plugin. I will use a forked version, bump to 2.0, and run the integ tests using OpenSearch core 2.0.0 to highlight any initial problems.

[amitgalitz]

In addition it seems like we return "type:_doc" on responses to delete API, search detector and search detector tasks or results on Opensearch 2.0.0