UI level QA

@satazor @marcooliveira Please find below some details to be revise/confirm:

• Fix “comment section” for the new height (60px);
• Add “skew” transform on comments once they're presented on both scroll up and down;
• What’s happening on the -2px of vertical alignment of “D-icon” inside the FAB;
• Stroke when hovering the FAB is missing;
• Replace the “comment-placeholder” after X seconds to the “comment-error”;
• Revisit header once we can include the new “features” for the version already designed, which includes:
  • Avatar;
  • Settings;
  • Online peers;
  • All my discussions;
  • Pinning status TBD: Delivered / Failed / Saved / Synced;
• How to manage page scroll when the user is only focused on the sidebar;