text: Title: Proof of concept #5593 - inline SVG icon for icon-contacts
  Body: I added `core/img/places/contacts.svg` icon inline, replacing CSS implementation as `background-image`
  
  This would solve some weird css class names and allow for a great flexibility with theming icons.
  
  it should work across all supported browsers.
  
  I also noticed that an almost identical icon is used in dropdown settings menu in lib/private/NavigationManager.php#211 - this solution would work there as well, but it would require changing the toggle method.