Build the claimChallenge JSon string using C# anonymous types for better readbility/maintenability

[jmprieur]

Please provide us with the following information:

This issue is for a: (mark with an x)

- [ ] bug report -> please search issues before submitting
- [ x ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

This line is hard to read, and write/modify and the compiler cannot verify if the JSon is well formed.

Expected/desired behavior

Proposing to change

tring claimsChallenge = "{\"id_token\":{\"acrs\":{\"essential\":true,\"value\":\"" + savedAuthContextId + "\"}}}";

into the following block, which uses C# anonymous types:

// Ask to have the optional claim named `acrs` in the ID Token.
// This claim will be essential, and its value will be `savedAuthContextId`
var claimsChallengeObjet = new
{
  id_token = new
  {
    acrs = new
    { 
      essential = true,
      value = savedAuthContextId
    }
  }
};
string claimsChallenge = JsonSerializer.Serialize(claimsChallengeObjet);

The same change would apply to the README.md file.

[jmprieur]

@kalyankrishna1: I thought you might be interested in this.

[kalyankrishna1]

A concrete serializable to json struct will be most welcome. Let me try implementing this

[jmprieur]

@kalyankrishna1 : with the optional claims, anonymous classes might be better than a strongly typed structure. Did you have in mind a strongly typed structure? We have this request in MSAL.NET, and I was tempted to advice the anonymous object route as it's super similar to https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-optional-claims#optional-claims-example

[aremo-ms]

@kalyankrishna1 still on it?