Theserviceisresponsibleforthepresentationoftheloadingbar.ItinjectstheloadingbarintotheDOM,adjuststhewidthwhenever`set()` is called, and `complete()`sthewholeshowbyremovingtheloadingbarfromtheDOM.
**`cfpLoadingBar:started`** triggered once upon the first XHR request. Will trigger again if another request goes out after `cfpLoadingBar:completed`hastriggered.