FontChoice plugin - add fix for Firefox

Firefox seems to wrap the font name with doublequotes, preventing it
form being properly selected.

Fixes #18387.
Remove unused parameter from factory function, refs #13035.

Like other widgets, still listing "dojo/i18n!../nls/loading" as a module dependency
so that there's no XHR (in AMD mode), and so the bundle is brought in during a build.