Extracted information from the tree, in a form that is readily accessible
for printing. I.e. resolve parent-child pointers into an actual tree,
zip permissions with their tag, remove wrappers, stringify data.
List of all events that affected a tag.
NOTE: not all of these events are relevant for a particular location,
the events should be filtered before the generation of diagnostics.
Available filtering methods include History::forget and History::extract_relevant.