Add ContentLanguage to header collection of GetObjectResponse.

[GarrettBeatty]

Stacked PRs:

• Add DownloadInitiated, Failed and Completed events #4079
• Add UploadWithResponseAsync API #4062
• Add GetObjectResponse to TransferUtilityOpenStreamResponse mapping. #4076
• Add DownloadResponse mapping #4075
• ->Add ContentLanguage to header collection of GetObjectResponse. #4074

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Add ContentLanguage to header collection of GetObjectResponse.

Motivation and Context

To make it easier to copy header values beteween GetObjectResponse and TransferUtilityDownloadResponse. Without this change i would have to manually copy contentLanguage from the property to TransferUtilityDownloadResponse's header collection rather than just copying the full header collection like we are already doing.

Testing

1. ran test locally
2. dry run d2b3cd95-f2ea-4a06-a535-a9ae116fb006 pass

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