examples/ip_pipeline: add flow id parameter to flow classification

examples/ip_pipeline: add flow id parameter to flow classification

This patch adds flow id field to the flow
classification table entries and adds table action
handlers to read flow id from table entry and
write it into the packet meta-data. The flow_id
(32-bit) parameter is also added to CLI commands
flow add, flow delete, etc.

Signed-off-by: Jasvinder Singh <jasvinder.singh@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>