Add DNS Resolution to gsutil -D Debug Output

[juanfdez404]

Currently, the gsutil -D debug output shows the hostname (e.g., storage.googleapis.com) used for accessing Google Cloud Storage resources. However, it doesn't provide the resolved IP address. This information would be valuable for troubleshooting, particularly in scenarios where:

• Private Service Connect endpoints are used: We need to confirm if the connection is going to the expected private IP address.
• Network issues are suspected: Knowing the resolved IP can help in diagnosing network connectivity problems.

Suggested Enhancement:

Include the resolved IP address(es) in the gsutil -D output, potentially like this:

[DEBUG] Using endpoint: storage.googleapis.com (resolved to 142.250.185.206)

This enhancement would improve the debugging experience for users working with complex network setups or those needing deeper insights into gsutil's network behavior.