Update the samples from .Net Framework to Dotnet 8

[SierraNL]

Most of the samples are .Net Framework, please update the samples to use Dotnet 8.
For some samples there will be no difference, But ClientLibraryConsoleAppSample isn't working anymore, since there is no authentication popup support for dotnet anymore, or working NTLM.

And I had to use a lot of googling to get it working using Azure.Identity.InteractiveBrowserCredential, the scope "499b84ac-1321-427f-aa17-267ca6975798/.default" and VssOAuthAccessTokenCredential