Update web-search-client-library-csharp.md

[Mohammed-Deifallah]

The documentation is outdated as it uses the deprecated package Microsoft.Azure.CognitiveServices.Search.WebSearch. It is the first step to update the documentation using the package Microsoft.Bing.Search.WebSearch

[learn-build-service-prod]

Learn Build status updates of commit ac56b7e:

💡 Validation status: suggestions

File	Status	Preview URL	Details
bing-docs/bing-web-search/quickstarts/sdk/web-search-client-library-csharp.md	💡Suggestion	View	Details

bing-docs/bing-web-search/quickstarts/sdk/web-search-client-library-csharp.md

• Line 12, Column 12: [Suggestion: ms-author-invalid - See documentation] Invalid value for 'ms.author', 'scottwhi' is not a valid Microsoft alias.

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[learn-build-service-prod]

Learn Build status updates of commit 079dc93:

✅ Validation status: passed

File	Status	Preview URL	Details
bing-docs/bing-web-search/quickstarts/sdk/web-search-client-library-csharp.md	✅Succeeded	View

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