app/proc-info: support xstats by ID and by name
app/proc-info: support xstats by ID and by name

There are new arguments --xstats-ids and --xstats-name
in proc_info command line to retrieve statistics given by ids
and by name.
E.g. --xstats-ids="1,3,5,7,8"
E.g. --xstats-name rx_errors

Signed-off-by: Kuba Kozak <67670b66df7eb69a86e2579475d68b34f383c70c@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk