examples/ip_pipeline: add rule list per table

examples/ip_pipeline: add rule list per table

For each pipeline table, have the master thread maintain the list of
rules that are currently stored in the table. This list allows the
master thread to handle table queries with minimal impact for the
data plane threads: requests to read the current set of table rules
are fully handled by the master thread with no involvement from
data plane threads, requests to read the per table rule moving data
(such as stats counters or timestamp associated with specific
actions) are handled by the data plane threads through plain memory
reads rather than key lookup.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Signed-off-by: Jasvinder Singh <jasvinder.singh@intel.com>
Signed-off-by: Hongjun Ni <hongjun.ni@intel.com>