Failure to instantiate a websocket endpoint is now properly reported

[lorban]

Closes #9412

[joakime]

The Jakarta WebSocket Spec has a jakarta.websocket.DeploymentException that we have to be careful to implement properly.

[lorban]

@joakime The EE10 DeploymentException javadoc says Checked exception indicating some kind of failure either to publish an endpoint on its server, or a failure to connect a client to its server. EE 9 and 8 versions of this class have identical javadoc.

If my understanding of what you're saying is correct:

• On the server, the CustomUpgradeServlet used in ProgrammaticWebSocketUpgradeTest should get a DeploymentException in response to its ServerContainer.upgradeHttpToWebSocket() call.
• On the client, WebSocketContainer.connectToServer() should throw DeploymentException.

I can make the necessary changes, but it looks like Jetty 11 also does not respect this contract.

[lorban]

@joakime I think there is indeed an issue with DeploymentException so I've opened #9466 to track it, and I'm going to happily ignore it in the context of this PR as it's out of this scope IMHO.