Add-ons Search Improvements 2.16.2

• Improve 3rd party support for specialized search index support

• Add additional hookpoints for customizing "specialized search indexer" functionality
• On search results page, when searching a conversation(XF2.2)/direct message(XF2.3) display "with conversation/direct message"

• Search extensions API changes for better XF compatibility, required for Conversation Improvements/Essentials
  • XF2.3 compatibility fix for custom "SearchOrder" class
  • Simplify asSqlConstraint code (expected to always return an array)
  • AbstractConstraint::setMatchType needs to normalize to an int for MetadataConstraint::matchType