[Xon] Lazy Load 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

• Require StandardLib v1.20.0+
• XF2.3 support

• Require php 7.2+
• Require StandardLib 1.18.0+
• Require XenForo 2.2+
• Confirm initial XF2.3 compatibility

• Prevent doubling images on selecting text/images under a spoiler & using quote/reply feature.

• Requires php 7.0+
• Require Standard Library by Xon
• Rename various options to be consistantly named
• Support XF2.2, various options now support disabling native XF2.2 native lazy loading