Allow to create a WebSocketContainer passing HttpClient

[sbordet]

Jetty version
10.0.x

Description
Client applications that want to use JSR WebSocket should be able to pass HttpClient to support TLS and have more configuration flexibility.

This is currently not possible because JavaxWebSocketClientContainer is in an internal package and not unconditionally exported.

However, JavaxWebSocketClientContainerProvider is accessible, so perhaps adding public static WebSocketContainer getContainer(HttpClient) will allow applications to create JSR WebSocket clients with the required flexibility.

[sbordet]

Furthermore, the JavaxWebSocketClientContainer(HttpClient httpClient) constructor should not change the name of the HttpClient, since it is provided externally and not owned by the client container.