Support for extraQueryParameters in Blazor WASM / MSAL

[umlaufa1]

Issue
I would like to pass a query parameter to a B2C user flow when authenticating my Blazor client app. The query parameter could be used, for example, to change the content on the login screen or lots of other useful things

B2C supports this through their IdentityExperienceFramework. Specifically, you can add the following to your user flow:

<InputClaims>
        <InputClaim ClaimTypeReferenceId="QueryParamName" />
</InputClaims>

MSAL also supports extra parameters using the "extraQueryParameters" type in AuthenticationParameters (https://docs.microsoft.com/en-us/azure/active-directory/develop/msal-js-pass-custom-state-authentication-request)

It appears WASM.Authentication.Msal does not provide access to extraQueryParameters.

Solution I'd like to see
Ideally, I would like the following behavior:

1. A user goes to http://www.myblazorapp.com/customID
2. CustomID is extracted from URL.
3. CustomID passed to my B2C user flow as a query parameter. (This doesn't appear to be supported)
4. My B2C user flow uses the CustomID.

Other Info
I think I could achieve a similar result with a"loginHint" but WASM.Authentication.Msal doesn't appear to support this either. The use of extraQueryParameters would provide the most flexibility. I have not been able to find any interim solution that lets me pass custom state info from my blazer app to a b2c userflow (I hope I am not missing something obvious :- ) )

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[johnnybegood]

The extra query parameters are also needed when calling an API that requires interaction: https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-conditional-access-dev-guide#scenario-app-performing-the-on-behalf-of-flow.