First pass at making Jetty 10.x require JDK 11.
* Removed JDK 8 modules (in particular ALPN and ALPN *.mod files).
* Removed profiles targeting JDK 8, 9 and 10.
* Updated dependencies to newer versions that support JDK 11.
* Temporarily commented out the Jetty Maven Plugins due to
maven-plugin-plugin not working with JDK 11.
Signed-off-by: Simone Bordet <simone.bordet@gmail.com>