Migrating from Microsoft.AspNetCore.Authentication.AzureAD to Microsoft Identity Web authentication library to integrate with Azure AD.

I recently had a chance to clean up some of the deprecated libraries I used for validating a JWT access token or obtain one via the client-credentials flow or the on-behalf-of flow. The libraries I used were under the Microsoft.AspNetCore.Authentication.AzureAD packages. Per the document, since ASP.NET core 5.0, users should use the Microsoft.Identity.Web package to integrate with Azure AD and Azure ADB2C.