Refactor inference runner for profiling mode

The inference runner has been refactored to store command line options
in a struct so that they can be passed around more easily and the
inconsistent std namespace usage has been cleaned up. This has been done
in preperation for adding profiling support.

Change-Id: I981ec1fbeaf28d568f2e948506f1b71418c1bba6
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>