made ajaxLink property an absolute url

[panteliymas]

When a site is located in subdirectory but not the root folder (site.com/sub/ and not the site.com/) async widgets will send request to root (site.com/arrilot/load-widget and not site.com/sub/arrilot/load-widget) so widgets are not loaded. I changed ajaxLink property of JavascriptFactory to be absolu url that is generated by laravel automatically (e.g. from .env with APP_URL)