Performance problem in JarFileResourceLoader

JarFile and ZipFile lock for just about anything. WildFly deployment iterates many shared modules, all of which are backed by JAR files. Deploying many archives in parallel can cause massive contention on these JAR files from iteration operations.

We don't need to iterate the JarFile every time; we can just grab a snapshot copy of the list of regular files in the JAR and traverse that instead.