Add overloads with explicit class loader to com.schibsted.spt.data.jslt.FunctionUtils #197

... and consider changing the existing FunctionUtils methods to use current thread's context class loader as a fallback. This is because in complex class loader environments (like Jboss Modules or Quarkus) the loader of the class calling FunctionUtils.wrapStaticMethod() may be unable to load the requested class. Current thread's context class loader is typically a good choice in situations like this one.

I could prepare a PR if this sounds good to you?