Plugin not serving js files best practice way

[tessa-fabry]

This core moodle bug is causing js files to be served directly https://tracker.moodle.org/browse/MDL-72461

Files should generally never be served directly by apache or nginx, they should go through one of the moodle file serving apis so that they are correctly served with the right caching headers to make them work with intermediate proxies and CDN's

If nginx is set up the best practice way this plugin will break. This tracker details how that should be set up https://tracker.moodle.org/browse/MDL-69333