Add-ons Report Improvements by Xon 2.20.6

• Require StandardLib v1.21.0+
• Restore XF2.1 support
• XF2.3 support
• php 8.4+ compatibility fixes
• Fix "Resolve report" would display on the "manage reply bans" page even if the user couldn't resolve any reports

• Workaround XF bug when a hinted event handler is called without any hint
• Compatibility fix with Report Center Essentials v2.12.0 and earlier. Recommend updating to Report Center Essentials v2.12.1+

• Fix "Maximum non-moderator users who can handle reports" option being ignored and defaulting to 1000
• Fix edge-case where users where unexpectedly returned as being assignable to a report when unexpected data was in the xf_user_group_relation table
• Increase cache time for report assignable list from 5 minutes to 1 hour, and add active expiring when permissions are changed