sadf: Add new output format: raw (part 1)

sadf: Add new output format: raw (part 1)

Add a new output format to sadf to display statistics saved in a binary
data file in raw format. Counters values are displayed "as is", without
trying to calculate an average value over the elapsed time interval.
This is something I have selfishly wanted to have for a long time now,
mainly for debugging purpose.
This first patch adds all the necessary global functions, and implements
the raw format only for CPU and task creation/system switching
statistics.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>