feat(gcp_cloud_storage sink): add content_encoding and cache_control options

[benjamin-awd]

Summary

This PR allows content_encoding and cache_control to be configured in the GCS sink.

Vector configuration

sources:
  test_logs:
    type: demo_logs
    format: json
    interval: 1.0
    count: 100

transforms:
  process:
    type: remap
    inputs:
      - test_logs
    source: |
      .timestamp = now()
      .message = .message
      .level = "info"
      .host = .host

sinks:
  gcs:
    type: gcp_cloud_storage
    inputs: [process]
    bucket: test_bucket123
    framing:
      method: newline_delimited
    encoding:
      codec: json
    compression: gzip
    content_encoding: ""
    cache_control: no-transform
    key_prefix: encoding_test

How did you test this PR?

Ran locally, verified in GCS that metadata is correct

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

• Closes: Add content_encoding and cache_control to gcp_cloud_storage sink #24505
• Related: feat(gcp_cloud_storage sink): add content_type option #24477
• Related: Feature Request: Add content_type option to gcp_cloud_storage sink #24410

Notes

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