Changing right bar icon + fixing issue with user info

This commit changes the right bar icon to the one [here](https://github.com/MtMNC/Refreshed/blob/patch-5/refreshed/images/icon-rightbar.png) and constrains the left bar's width on mobile so it doesn't block part of the site info when the window is too small. Also, the right bar icon is now a background image and not an img element.