Id to path mapping and finding objects

[marcolarosa]

The repository find method emits a JS object with ocfl root and path of the object located but we really want it to return an id as well.

However, if the id has been hashed before turning into a path on the FS we need to load the ocfl inventory file to extract the id. Currently it looks like the id is the mapped id - that coming in to the library - not the id before any transformations.