flow-accounting: T2695: Fixed crash on viewing flows with incomplete data
flow-accounting: T2695: Fixed crash on viewing flows with incomplete data

If flow records contain entries with skipped details, this does not allow preparing it for the output table. This fix use safe .get() function to return empty values instead crashing.
Also, added several small formatting fixes.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x