net/mlx5: fs, add HWS actions pool

The HW Steering actions pool will help utilize the option in HW Steering
to share steering actions among different rules.

Create pool on root namespace creation and add few HW Steering actions
that don't depend on the steering rule itself and thus can be shared
between rules, created on same namespace: tag, pop_vlan, push_vlan,
drop, decap l2.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250109160546.1733647-5-tariqt@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>