net/mlx5: DR, Split modify VLAN state to separate pop/push states

Split modify vlan state in the actions state machine to pop vlan
and push vlan states. This enables using of pop/push vlan without
restrictions (e.g. pop vlan on TX in STEv1).

Signed-off-by: Muhammad Sammar <muhammads@nvidia.com>
Signed-off-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>