app/testpmd: support policy actions per color

Add the create/del policy CLIs to support actions per color.
The CLIs are:
Create:  add port meter policy (port_id) (policy_id) g_actions (actions)
y_actions (actions) r_actions (actions)
Delete:  del port meter policy (port_id) (policy_id)

Examples:
testpmd> add port meter policy 0 1 g_actions rss / end y_actions end
r_actions drop / end
testpmd> del port meter policy 0 1

Signed-off-by: Haifei Luo <haifeil@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>