pipeline: add table action APIs

pipeline: add table action APIs

This API provides a common set of actions for pipeline tables to speed up
application development.

Each match-action rule added to a pipeline table has associated data
that stores the action context. This data is input to the table
action handler called for every input packet that hits the rule as
part of the table lookup during the pipeline execution.

The pipeline library allows the user to define his own table
actions by providing customized table action handlers (table
lookup) and complete freedom of setting the rules and their data
(table rule add/delete). While the user can still follow this
process, this API is intended to provide a quicker development
alternative for a set of predefined actions.

The typical steps to use this API are:
* Define a table action profile.
* Instantiate the table action profile to create table action objects.
* Use the table action object to generate the pipeline table action
  handlers (invoked by the pipeline table lookup operation).
* Use the table action object to generate the rule data (for the
  pipeline table rule add operation) based on given action parameters.
* Use the table action object to read action data (e.g. stats counters)
  for any given rule.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>