SignalR ConnectionToken/ConnectionAddress feature (#13773)

...rp/Client/test/UnitTests/HttpConnectionTests.Negotiate.cs

...alR/clients/csharp/Client/test/UnitTests/ResponseUtils.cs

...ents/csharp/Http.Connections.Client/src/HttpConnection.cs

...icrosoft.AspNetCore.Http.Connections.Common.netcoreapp.cs

...soft.AspNetCore.Http.Connections.Common.netstandard2.0.cs

...R/common/Http.Connections.Common/src/NegotiateProtocol.cs

...common/Http.Connections.Common/src/NegotiationResponse.cs

...on/Http.Connections/src/Internal/HttpConnectionContext.cs

...Http.Connections/src/Internal/HttpConnectionDispatcher.cs

...on/Http.Connections/src/Internal/HttpConnectionManager.cs

...on/Http.Connections/test/HttpConnectionDispatcherTests.cs

...ommon/Http.Connections/test/HttpConnectionManagerTests.cs

...lR/common/Http.Connections/test/NegotiateProtocolTests.cs