[mod] finder becomes the path module
[mod] extract path
[mod] don't produce useless lines
[enh] add node_to_bounding_box
[fix] use string_instance
[mod] merge key, list and formatting rendering
[mod] do not walk on empty list

Else, it calls before and after
[mod] removed unused complexity in test_render
[mod] add tests for render walker
[mod] remove unneeded class handling path
[enh] add path walker based on render walker

It adds the current path as an attribute while walking the FST
[mod] be consistent by really going to the leaf

Path walker does the same thing
[mod] render also constants
[mod] add path to bounding box

This means refactoring the tests to allow automatic bounding box
checking
[mod] simplify stop condition by implying continue