The current algorithm returns a random result unless a is in b's type hierarchy.  Random results are disallowed in the sort_custom API

https://docs.godotengine.org/en/3.5/classes/class_array.html?highlight=sort_custom

The new algorithm sorts alphabetically by names in the type hierarchy paths until one of the trees stop then it sorts the shorter tree first.

Aims to fix the following errors that gets spammed at startup (and i think causes startup crashes):

E 0:00:00.815   SortArray<class Variant,struct _ArrayVariantSortCustom,1>::partitioner: bad comparison function; sorting will be broken
  <C++ Source>  .\core/sort_array.h:179 @ SortArray<class Variant,struct _ArrayVariantSortCustom,1>::partitioner()
  <Stack Trace> script_extension.gd:39 @ handle_script_extensions()
                mod_loader.gd:164 @ _load_mods()
                mod_loader.gd:67 @ _init()