Make JLine3Feature usable with image-builer on module-path

[olpaw]

@boris-spas this change allows us to use the JLine3Feature when the image-builer runs on module-path.

In this case launcher-common.jar is on the module-path and loaded as module org.graalvm.launcher. In this scenario ClassLoader.getSystemResourceAsStream does not work anymore and we have to use JLine3Feature.class.getModule().getResourceAsStream(resourcePath).

Unfortunately using that directly would break using launcher-common.jar on Java 8. Thus this is instead done reflectivity. On Java 8 we are falling back to using ClassLoader.getSystemResourceAsStream(resourcePath) which is safe because on 8 launcher-common.jar can only ever end up on the classpath.

[olpaw]

Btw, I tested that this works with

• Java 11 with the image-builder
  -- running on module-path
  -- running on classpath
• Java 8 with image-builer (on classpath, obviously)