Signup abuse detection and blocking 1.19.0

• Fix 'attempt to read property "group_id" on null' error on viewing trophies

• Fix Team Cymru IP to ASN integration failing for ASN's shorter than 4 digits, also a php 8 compatibility fix.

• Fix the "External API query cache time" option was being ignored
• Fix php 8+ compatibility issue with LinkChecker

• Fix MySQL 8+ compatibility when upgrading

• Remove the defunct Apility.Io as an geoip/asn lookup provider.
• Add external API caching support (default cache time is 12 hours, adjustable), with XF cache context support ('spamCheckCache')

• Remove unexpectedly wide locking on user table during multi-account detection

• Fix admincp multi-account list pagination not generating correct links

• Fix SFS and Project HoneyPot lookup being triggered twice
• Fix showing last activity for guests in tickets in moderation queue

• Requires php 7.0+
• Now depends on Standard Library by Xon
• Confirm XF2.2+ support

• Update installer to not wipe the "Link Spam checker" URL options. Retrieving this information can be done via using SQL to find the last update and manually extract it from the relevent json;
  SQL:

  select * 
  from xf_admin_log 
  where request_data like '%svLinkSpamCheckerBlackList%'
  order by 1 desc limit 1;