file picker: getting the path to the file under the cursor

**Is your feature request related to a problem? Please describe.**
I'd like to be able to use the file/directory that the cursor is currently on without having to "select" it. This would give me the ability to execute multiple distinct actions with the file picker and not be limited the only select.

**Describe the solution you'd like**
Expose a public method on the file picker model that returns the file/directory under the cursor.

**Describe alternatives you've considered**
- It may be possible to keep track of the path outside of the file picker.
- One could argue that this functionality does not belong in a file picker, and in that case I'd have to create a custom component which is very similar.