20225: Add subdirectory selection support to directory input

20225: Add subdirectory selection support to directory input

Converts getFileOperationLocation into a dispatchable helper so it can access
the store to augment FileOperationLocations with a PDH

Converts DirectoryTreePickerField into a connected class component in order to
use getFileOperationLocation

Change DirectoryInputComponent to include directories in the picker and use
getFileOperationLocation to pass FileOperationLocation instead of Collection
objects so that the subpath within the collection can be embedded in the
Directory object

Arvados-DCO-1.1-Signed-off-by: Stephen Smith <stephen@curii.com>