Add s3 url in secret created by s3-operator

[Donatien26]

Description

Currently, the s3-operator creates the Kubernetes secret with the bucket credentials (access key, secret key, etc.), but the S3 bucket URL is not included.

Problem

Without the bucket URL, some applications need to manually reconstruct it or configure it separately, which complicates setup and increases the risk of misconfiguration.

Expected Improvement

• Automatically add the full S3 Service path_based URL (e.g., https://S3_URL) to the secret created by the s3-operator.
• The key could be named S3_SERVICE_URL (or similar) for consistency with other variables.
• Also add the S3_HOSTNAME

Benefits

• Simplifies configuration for applications consuming the secret.
• Reduces duplicated configuration and potential inconsistencies.
• Improves developer experience by making the secret directly usable.