The embedded servers should reset system properties

Some system properties are set when a standalone server or host controller are created with the embedded server API. When the embedded server is stopped these properties should be reset to their previous value if applicable.

Some system properties, such as module.path, cannot and should not be reset. With the ModuleLoader the module.path system property is effectively static and can only be set once.

There is no requirement to reset all system properties and overridden properties should be honored where applicable.