Exposed the server for subclasses.

[kittaakos]

Otherwise, subclasses cannot create the launcher in the overridden createLauncher method.

Signed-off-by: Akos Kitta kittaakos@typefox.io

[kittaakos]

Workaround for the time being:

@Inject
extension ReflectExtensions;
def private DiagramLanguageServer getLanguageServer() {
  return get('languageServer');
}