NetHttpBinding with WebSockets doesn't allow custom Certificate handling

[mconnew]

This involves:

1. Calling any custom X509CertificateValidator.Validate class that a user has set on their credentials for verifying the server cert.
2. Using the ClientCertificate that a user has provided on the credentials to authenticate against the server.
3. Most likely adding functionality to the System.Net.WebSockets.Client.ClientWebSocket class to enable certificate handling.

[mconnew]

The System.Net.WebSockets.Client and System.Net.WebSockets contracts do not facilitate any certificate handling. This will be addressed post RTM by the team which owns those contracts, until then we are blocked.

[zhenlan]

Thanks @mconnew. Can we add related System.Net.WebSockets.* issues here?