[Feature] WindowsProvider should support AAD login

[shweaver-MSFT]

Describe the problem this feature would solve

Currently WindowsProvider only supports MSA login. If a developer wants to support AAD, they must switch to use MsalProvider instead. The native WAM APIs support AAD login, the support just needs to be added.

Describe the solution

Enhance the WindowsProvider to handle AAD login and add an additional Aad value to the WebAccountProviderType enum.

By default, the WindowsProvider is already coded to handle All account types, so AAD should work without any additional configuration.

To ONLY target AAD login, WebAccountProviderType can be explicitly set using the new value, WebAccountProviderType.Aad.