crypt: change backend encode/decode to output a plain list
crypt: change backend encode/decode to output a plain list

This commit changes the output of the rclone backend encode crypt: and
decode commands to output a plain list of decoded or encoded file
names.

This makes the command much more useful for command line scripting.

ncw/rclone,ncw/rclone,ncw/rclone,ncw/rclone