[csharp-netcore] HttpClient/Use a CancellationToken with a timeout

Created by: TORISOUP

What is the issue

• Configuration.Timeout is not applied correctly using HttpClient.

Correction details

Fixed to use CancellationToken generated when configuration.Timeout is set. Using Declaration is not used for compatibility, and finally is used to avoid unnecessary allocations.

How to validate the work

• Set an extremely small value (e.g., 1 ms) in configuration.Timeout and execute the communication in production.
• At this time, check that a TaskCanceledException is thrown and the process is aborted.

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