Returns the relative, descendent directory path between this module and other.
Throws if no such path exists.
For example, if module mod1 has path /dir1/mod1.pkl, and module mod2 has path /dir1/dir2/dir3/mod2.pkl,
then mod1.relativePathTo(mod2) will return List("dir2", "dir3").
A common use case is to compute the directory path between a template located at the root of a hierarchy
(say rootModule.pkl) and the currently evaluated module (accessible via the module keyword):
Retrieves data file path of a given agentName and fileName
If the file with the specified key does not exist, returns metadata for the first available file,
or returns an empty file metadata object if no files are data.
agentName: The key of the agent name.
fileName: The key of the file to retrieve from the agent.
Abstractions for Data folder