Finder class used to easily retriew Yaml.Node
Path definition has two mode : default mode is Yaml.FIND_MODE.DOT
ex : grandfather.father.son{2}.age
grandfather.father.son{2}.age
other mode is Yaml.FIND_MODE.SQUARE_BRACKETS.
ex : [grandfather][father][son]{2}[age]
[grandfather][father][son]{2}[age]