examples/ip_pipeline: add flow actions pipeline

examples/ip_pipeline: add flow actions pipeline

Flow actions pipeline is an extension of flow-classification pipeline.
Some of the operations of flow classification pipeline such as traffic
metering/marking(for e.g. Single Rate Three Color Marker (srTCM), Two
Rate Three Color Marker trTCM)), policer can be performed separately in
flow action pipeline to avoid excessive computational burden on the CPU
core running the flow-classification pipeline. The Flow action pipeline
implements various function such as traffic metering, policer, stats.
Traffic mettering can configured as per the required context, for
examples- per user, per traffic class or both. These contexts can be
applied by specifying parameters in configuration file as shown below;

[PIPELINE1]
type = FLOW_ACTIONS
core = 1
pktq_in = RXQ0.0 RXQ1.0 RXQ2.0 RXQ3.0
pktq_out = TXQ0.0 TXQ1.0 TXQ2.0 TXQ3.0
n_flows = 65536
n_meters_per_flow = 1
flow_id_offset = 158
ip_hdr_offset = 142
color_offset = 64

The entries of flow and dscp tables of flow actions pipeline can be
modified through command-line interface. The commands to add or delete
entries to the flow table, DSCP(differentiated services code point)
table and for statistics collection, etc have been included. The key
functions such as Traffic Metering/marking and policer functions have
been implemented as flow-table action handler.

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