CORE-5042 Update save endpoint to not set info-type.

Refactored the filetype logic out of the scruffy-copy function and into the store function.
Added a save function that can be used by both the save endpoint and the store function.
CORE-5042 Updated file listings file-size to longs.

Changed file-size to a long rather than a string for consistency with other endpoints.
Updated documentation to reflect longs rather than strings for file-size, date-created, and date-modified fields.