Ensure list output function can support non-sorting printing

Ensure list printing function in utils can handle non-sorting
calls. Allow result list can be formatted and outputted without any
sorting field, keep natural order to the list printing. Adding necessary
checking to avoid prettytable (0.6.1 for me) exception: "Invalid field
name: None!".

Fix bug: #1099732

Change-Id: Ied869d987e608fff8b8b5f5a65d21e02f0cebeaa
Signed-off-by: zhiyanliu <lzy.dev@gmail.com>
Merge "Ensure list output function can support non-sorting printing"