rptest: Fix s3.copy_object when running on GCP

[savex]

When running boto3 client versus AWS it uses own header to point to object that needs to be copied.
The same function is usable for GCP's storage, but with custom header.

This PR adds custom_headers handling to CopyObject function

Backport needed only to v23.3.x due to GCP runs only supported for that version
Also v23.1.x will reach end of support soon.

Fixes: #15211

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.3.x
• v23.2.x
• v23.1.x

Release Notes

• none

[savex]

Running on GCP env

ubuntu@rp-client-0-firstly-exciting-macaque:~/tests$  cd /home/ubuntu/tests ; /usr/bin/env /bin/python3 /home/ubuntu/.vscode-server/extensions/ms-python.debugpy-2024.0.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher 39305 -- -m ducktape --cluster=ducktape.cluster.json.JsonCluster --cluster-file=cluster.json --globals=globals.json --max-parallel=1 --repeat=1 --test-runner-timeout=86400000 rptest/tests/services_self_test.py::BucketScrubSelfTest.test_missing_segment 
[INFO:2024-02-01 15:23:09,186]: starting test run with session id 2024-02-01--004...
[INFO:2024-02-01 15:23:09,186]: running 1 tests...
[INFO:2024-02-01 15:23:09,187]: Triggering test 1 of 1...
[INFO:2024-02-01 15:23:10,128]: RunnerClient: Loading test {'directory': '/home/ubuntu/redpanda/tests/rptest/tests', 'file_name': 'services_self_test.py', 'cls_name': 'BucketScrubSelfTest', 'method_name': 'test_missing_segment', 'injected_args': {'cloud_storage_type': <CloudStorageType.S3: 1>}}
[INFO:2024-02-01 15:23:10,138]: RunnerClient: rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3: on run 1/1
[INFO:2024-02-01 15:23:10,154]: RunnerClient: rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3: Setting up...
[INFO:2024-02-01 15:23:16,427]: RunnerClient: rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3: Running...
[WARNING - 2024-02-01 15:24:31,233 - redpanda - stop_and_scrub_object_storage - lineno:4067]: Non-fatal anomalies in remote storage: {
  "anomalies": {
.....
[INFO:2024-02-01 15:25:07,872]: RunnerClient: rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3: PASS
[INFO:2024-02-01 15:25:07,873]: RunnerClient: rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3: Data: None
test_id:    rptest.tests.services_self_test.BucketScrubSelfTest.test_missing_segment.cloud_storage_type=CloudStorageType.S3
status:     PASS
run time:   1 minute 57.734 seconds
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
===============================================================================================================================================================================================================================================================================================================================
SESSION REPORT (ALL TESTS)
ducktape version: 0.8.18
session_id:       2024-02-01--004
run time:         1 minute 59.324 seconds
tests run:        1
passed:           1
flaky:            0
failed:           0
ignored:          0
opassed:          0
ofailed:          0
===============================================================================================================================================================================================================================================================================================================================

[abhijat]

lgtm

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/44593#018d6586-29b8-4f73-a3c2-c48abd1c49b3

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/44593#018d6586-29bc-4acb-a9b1-19a6df8a53d4

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/44593#018d6597-3bf7-4728-a97b-88ba7bbb77d1

[vbotbuildovich]

/backport v23.3.x