Previously, when the embedded Undertow container was stopped, the
servlet deployment was stopped but it was not undeployed. This meant
that contextDestroyed() callback of any registered
ServletContextListeners was not called.

This commit updates UndertowEmbeddedServletContainer to call undeploy
on the deployment manager in addition to the existing call to stop.
Undeploying the servlet deployment calls Undertow to drive the
contextDestroyed callback on any registered ServletContextListeners.

Closes gh-13134