Add DownloadInitiated, Failed and Completed events

[GarrettBeatty]

Stacked PRs:

• Populate TransferUtilityDownloadDirectoryResponse with total objects downloaded #4109
• ->Add DownloadInitiated, Failed and Completed events #4079

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Description

This change adds progress listeners for "initiated", "complete", and "failed" lifecycle events for the DownloadCommand Consumers can subscribe to these callbacks to receive notifications when a simple upload starts, finishes successfully, or fails. Its similar to #4059 but for downloads

Motivation and Context

1. To adhere to the SEP

Testing

1. f0cb4050-fb2c-4fb0-b489-280eb3313ca9 - pass
2. Integration tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license

[Copilot]

Pull Request Overview

This PR adds lifecycle events (DownloadInitiatedEvent, DownloadCompletedEvent, and DownloadFailedEvent) to the S3 TransferUtility download functionality, providing developers with better visibility into download operations.

Key changes:

• New event handlers and event argument classes for download lifecycle events
• Integration of events into the DownloadCommand execution flow
• Comprehensive integration tests covering individual and combined lifecycle events

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
sdk/src/Services/S3/Custom/Transfer/TransferUtilityDownloadRequest.cs	Adds three new public events (DownloadInitiatedEvent, DownloadCompletedEvent, DownloadFailedEvent) with corresponding event argument classes and internal event-raising methods
sdk/src/Services/S3/Custom/Transfer/Internal/_async/DownloadCommand.async.cs	Implements event firing at appropriate points in the download lifecycle, tracks total bytes from response headers, and maps the final response
sdk/src/Services/S3/Custom/Transfer/Internal/DownloadCommand.cs	Adds event firing helper methods and tracks total transferred bytes using Interlocked operations for thread safety
sdk/src/Services/S3/Custom/Model/GetObjectResponse.cs	Adds Request property to WriteObjectProgressArgs to provide access to the original download request
sdk/test/Services/S3/IntegrationTests/TransferUtilityTests.cs	Adds five new integration tests covering individual events and complete lifecycle scenarios
generator/.DevConfigs/9d07dc1e-d82d-4f94-8700-c7b57f872123.json	Adds dev config for version bump

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.