ES: do not set _type when using Bulk API for v7 client

[mantas-sidlauskas]

What changed?

• Do not set _type field for Bulk API request when using ES7 client
• Added integration test to check ES7 client compatibility with OpenSearch 2

Why?
This is done to align with changes made in OpenSearch 2, based on Elasticsearch plan

Eventually, Cadence should switch to official Elasticsearch/OpenSearch clients as current client is not developed anymore and will have no support for upcoming ES versions

How did you test it?
Unit tests/integration tests/local test

Potential risks

Release notes

Documentation Changes

[coveralls]

Pull Request Test Coverage Report for Build 0186c9e8-0b0e-4f10-85d1-7c53b7838aae

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 41 unchanged lines in 8 files lost coverage.
• Overall coverage increased (+0.06%) to 57.188%

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Files with Coverage Reduction	New Missed Lines	%
common/task/fifoTaskScheduler.go	2	87.63%
common/task/weightedRoundRobinTaskScheduler.go	2	89.12%
service/history/execution/mutable_state_builder.go	2	68.76%
service/history/shard/context.go	2	66.52%
common/cache/lru.go	3	90.73%
service/history/decision/task_handler.go	5	72.33%
service/history/task/transfer_standby_task_executor.go	8	86.4%
service/history/execution/mutable_state_task_refresher.go	17	61.71%

Totals
Change from base Build 0186c950-a929-4d6d-8e7e-ccca6e641184:	0.06%
Covered Lines:	85191
Relevant Lines:	148967

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💛 - Coveralls

[Shaddoll]

Thanks!

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