Fix S3 client clone

[antonio2368]

Changelog category (leave one):

• Bug Fix (user-visible misbehavior in an official stable release)

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

Fix using native copy on GCS for backups. Because of incorrect client cloning, GCS native copy always failed and used less optimal approach of manual reading and writing the data.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

[clickhouse-gh]

Workflow [PR], commit [0dcb494]

Summary: ❌

job_name	test_name	status	info	comment
PR formatter		failure
	check output	failure	cidb
Stateless tests (amd_binary, old analyzer, s3 storage, DatabaseReplicated, parallel)		failure
	03712_json_advanced_shared_data_bug	FAIL	cidb
Integration tests (amd_binary, 2/5)		failure
	test_kafka_bad_messages/test.py::test_bad_messages_parsing_stream	FAIL	cidb
	test_kafka_bad_messages/test.py::test_bad_messages_parsing_dead_letter_queue	FAIL	cidb
	test_kafka_bad_messages/test.py::test_bad_messages_parsing_exception	FAIL	cidb
	test_kafka_bad_messages/test.py::test_bad_messages_to_mv	FAIL	cidb
BuzzHouse (amd_debug)		failure
	Buzzing result	failure	cidb
BuzzHouse (arm_asan)		failure
	Buzzing result	failure	cidb
BuzzHouse (amd_ubsan)		failure
	Buzzing result	failure	cidb
Finish Workflow		failure
	python3 ./ci/jobs/scripts/workflow_hooks/new_tests_check.py	failure

[nikitamikhaylov]

@antonio2368 Time to think how to write good tests for it:

We repeatedly fix the same problem in the same place...

[antonio2368]

Time to think how to write good tests for it

The issue is we are working around the specific behavior of GCS so I don't see a way to test it correctly unless we connect to it directly.

Also, the source of all those issues is using AWS client for GCS interaction which we reverse engineer based on the responses we get (+ it changes constantly). Using native client would definitely help.

[nikitamikhaylov]

@antonio2368 I was thinking about checking it from the C++ standpoint. For example to write a private operator== and having the unit test that checks that a cloned client equals to an original one.

However, this test won't fail in case if you add a new field to the class and don't update the operator==/copy constructor.

[nikitamikhaylov]

CI experiences some instability. Not related to the PR, because we have no real tests on top of GCP.