Remove change_list template, set path in JS

admin-sortable wasn't working on my list page and it took me a while to figure out why: I was using a custom `template_change_list`. Since the admin-sortable one is only used to set a hard-coded path, I moved that definition into the JS. This should make admin-sortable more flexible with regards to templates.

Do let me know if this is suboptimal, I might be missing something I haven't considered.