Search Improvements 2.15.6

• Fix guest user searches could be sent into a redirect loop depending on search criteria

• Fix XF2.3.0 infinite search redirect for guests

• Restore XF2.1 support
• XF2.3 support
• Fix "[E_DEPRECATED] Use of "parent" in callables is deprecated" on search

• Add "Push thread prefix text into search" option (default true)
  • Supports ElasticSearch Essential's autocomplete
  • Requires manual rebuild of threads on changing this option

• Fix guests searching by user would restart the search query the first time they tried to visit the a different page of the search results

• Requires StandardLib v1.19.0+
• If installed, requires Redis Cache 2.17.0+
• XF2.3 compatibility update
• php 8.4 compatibility fix

• Require StandardLib v1.19.0+
• Code cleanup
• Add getSearchIdFromEntityId() helper method for transforming an XF entity id into the Elasticsearch index id

• Workaround XF2.2.13 does the search before checking it it can save it as a cached value, which can result in a query that is massively more complex than expected being sent to elasticsearch
  • This issue practically doesn't occur with stock XFES, but with additional search addons such as ElasticSearch Essentials this can generate unexpected errors

• Support tag/username autocomplete using XFES add-ons todo prefix matching on autocomplete

• Fix viewing the index list could be blocked when elasticsearch is configured but inaccessible