Is this sample, as it is, still functional?

Hello everyone!

We are migrating our WebApp and WebAPI to AAD B2C. Our projects are .NET Framework based so I think this example is the closest one to our use case.

I wonder if this sample in the repo is still usable and worth the time to make it work because I've been struggling the last few days. I couldn't find a newer example on how to implement AAD B2C with .Net Framework.

I'm new to Azure in general and I was reading a lot of documentation but I couldn't make this sample to work. First problem was in this section inside TasksController.cs:

```csharp
IConfidentialClientApplication cca = MsalAppBuilder.BuildConfidentialClientApplication();
string accountId = ClaimsPrincipal.Current.GetB2CMsalAccountIdentifier(Globals.SignUpSignInPolicyId);
var account = await cca.GetAccountAsync(accountId);
return await cca.AcquireTokenSilent(scopes, account).ExecuteAsync();
```
`GetAccountAsync` always returns null. I tried using `GetAccountsAsync` (it's deprecated) and it returns null also.
In this #109 issue the solution was to lower the policy id but it didn't work for me.

Thanks in advance!