Apostrophe 4.5.2: hotfix for regression affecting search when "ancestors" configuration is more inclusive

[boutell]

Starting with release 4.4.0, it has been possible for the search module to enter an infinite loop on the server side under certain conditions, e.g. circular references were possible in the data.

Starting with release 4.5.2, the apos.doc.walk method automatically detects circular references and does not pursue them.

This is a recommended upgrade for those using Apostrophe's full-site search feature and Apostrophe 4.4.0 or later. npm update or npm update apostrophe should be sufficient.

An additional, related bug fix: apos.doc.walk no longer lists each ancestor twice in the ancestors argument to the iterator function provided by the caller.