Today we reverse the initial order of the nested documents when we
index them in order to ensure that parents documents appear after
their children. This means that a query will always match nested documents
in the reverse order of their offsets in the source document.
Reversing all documents is not needed so this change ensures that parents
documents appear after their children without modifying the initial order
in each nested level. This allows to match children in the order of their
appearance in the source document which is a requirement to efficiently
implement #33587. Old indices created before this change will continue
to reverse the order of nested documents to ensure backwark compatibility.
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