Lazy Load [img] 2.8.0

• Require StandardLib v1.22.0+
• Support XF2.2+ width/height attributes for IMG/ATTACH tags and use an SVG with those exact dimensions to prevent page-reflows due to height changes
  • XF2.3 correctly sets the height attribute, while XF2.2 does not

Fix XF2.3 lightbox support

Fix javascript error when quoting a post via the 'reply' button with XF2.2