Search results debugging

[vladak]

Inspired by #4180 (comment), this change will log the documents found by a search at the FINEST level. The document ID and path will be logged so that one can see whether there are multiple documents with the same path and different ID.

Here's example of the output (for the second page of search results, hence the 25-37) range:

03-Mar-2023 17:48:01.868 FINEST [http-nio-8080-exec-124] org.opengrok.indexer.search.Results.createMap directory hash contents for search hits (25,37):
03-Mar-2023 17:48:01.875 FINEST [http-nio-8080-exec-124] org.opengrok.indexer.search.Results.createMap 5,631: /lucene/lucene/core/src/java/org/apache/lucene/index/PointValues.java
03-Mar-2023 17:48:01.876 FINEST [http-nio-8080-exec-124] org.opengrok.indexer.search.Results.createMap 6,403: /lucene/lucene/analysis/common/src/java/org/apache/lucene/analysis/email/UAX29URLEmailTokenizerImpl.jflex

It does not display the actual search query, that would require some sort of representation of the SearchHelper instance. Also, this is meant for very specific debugging, so it's not actually needed.