Add GCSToAzureBlobStorageOperator for GCS to Azure Blob transfer

[yuseok89]

Adds GCSToAzureBlobStorageOperator to copy objects from Google Cloud Storage to Azure Blob Storage.
There was no existing operator for this path (GCS → Azure Blob), so this fills that gap. The implementation follows the same overall patterns as S3ToAzureBlobStorageOperator.

Test Screenshots

Source files (GCS)

Default structure

Flatten structure

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