[DOCS] Add minimal specifications for all Elasticsearch API docs

[lcawl]

In order to retire the old API documentation, we need specifications for each API that appears in the old docs unless the API is internal or being removed. The following APIs do not yet appear in the OpenAPI document:

• Post event to an analytics collection Add specification for post event to an analytics collection #3363
• Update connector features Add specification for update connector features #3364
• Check in connector sync job Add specification for check in connector sync job #3365
• Claim connector sync job Add specification for claim connector sync job #3366
• Set connector sync job error Add specification for set connector sync job error #3367
• Set connector sync job stats Add specification for set connector sync job stats #3368
• Find field structure Add find field structure and find messages structure APIs #3346
• Find messages structure Add find field structure and find messages structure APIs #3346
• Get data stream lifecycle stats Add indices.get_data_lifecycle_stats #3418, Add missing ES|QL, data stream, inference, and PKI security specifications elasticsearch#119472
• ES|QL async query Add esql.async_query, esql.async_query_get, esql.async_query_delete #3398
• ES|QL async query get Add esql.async_query, esql.async_query_get, esql.async_query_delete #3398
• ES|QL async query delete Add esql.async_query, esql.async_query_get, esql.async_query_delete #3398, Add missing ES|QL, data stream, inference, and PKI security specifications elasticsearch#119472
• Stream inference Add inference.stream_inference and inference.update #3399
• Update inference Add inference.stream_inference and inference.update #3399, Add missing ES|QL, data stream, inference, and PKI security specifications elasticsearch#119472
• Simulate ingest Add simulate.ingest specification #3400
• Render search application query Add search_application.render_query #3401
• Delegate PKI authentication Add security.bulk_update_api_keys and security.delegate_pki #3402, Add missing ES|QL, data stream, inference, and PKI security specifications elasticsearch#119472
• Get security index settings Add security.update_settings and security.get_settings #3396
• Update security index settings Add security.update_settings and security.get_settings #3396
• OpenID connect prepare Add missing OpenID Connect security specifications #3393
• OpenID connect authenticate Add missing OpenID Connect security specifications #3393
• OpenID connect logout Add missing OpenID Connect security specifications #3393
• Bulk update API keys Add security.bulk_update_api_keys and security.delegate_pki #3402
• Repository analysis Add snapshot.repository_analyze #3403
• Update watcher settings Add watcher.get_settings and watcher.update_settings #3397
• Get watcher settings Add watcher.get_settings and watcher.update_settings #3397