[Feature Request] Make managed identity token parse failures distinct

[billwert]

MSAL client type

Managed identity

Problem Statement

In Azure Identity before we switched to using MI from MSAL, we were able to throw a distinct exception in the case of an invalid json response from the IMDS endpoint. This let us detect cases such as a proxy.

Proposed solution

We need ManagedIdentityApplication to notify us that the response was malformed json. .NET did this work here: AzureAD/microsoft-authentication-library-for-dotnet#5038 - we need roughly the same thing.

Alternatives

No response