Add FileSystemDataStorage Download Skip

[pickles-bread-and-butter]

Overview

The FileSystemDataStorage class will automatically copy files from src to dst when operating on a filesystem. This is important for mounted file systems (well I guess they're all techincally mounted but non local mounted) that don't have caching but for non mounted and ones with caching we want to remove this.

Acceptance Criteria

1. FileSystemDataStorage class now has an option to turn off the data downloading
2. Passes back just the file path that the user has requested without downloading, keeping the api the same

[pickles-bread-and-butter]

@aalavian @convexquad, I'll do this when I'm done with #57