User Mentions Improvements by Xon v2.10.1

• Require StandardLib v1.21.0+
• XF2.3 support
• php 8.4+ compatibility fixes

• Require php 7.2+
• Require StandardLib v1.18.0+
• Minor code cleanup, confirm support for one-click email unsubscribe header for XF2.2.15+

2.8.2 - Bugfix update​

• Fix cases where usergroup mentions could unexpectedly not match non-english titles
• Fix linking to report comment from mention email