Support multi-release JARs

[gastaldi]

Fixes #10756

[gastaldi]

Damn Windoze 😢. Something is locking the file and not closing it. Debugging again, but now in my Windows VM

[gastaldi]

The problem is with URL.openStream(). For some reason this locks the JAR file in Windows.
One way to fix that is to do:

            JarURLConnection urlConnection = (JarURLConnection) resource.openConnection();
            urlConnection.setUseCaches(false);
            try (InputStream is = urlConnection.getInputStream()) {
                IoUtils.copy(baos, is);
            }

But that's ridiculous, so I used cl.getResourceAsStream(..) instead

[jaikiran]

From what I remember, @aloubyansky had fixed (or added some workaround for this) when he had run into this while working on packaging related changes. I don't remember what that fix/workaround was.

[aloubyansky]

Right, avoid URL.openStream() for local paths.