openvswitch: include datapath actions with sampled-packet upcall to userspace

If new optional attribute OVS_USERSPACE_ATTR_ACTIONS is added to an
OVS_ACTION_ATTR_USERSPACE action, then include the datapath actions
in the upcall.

This Directly associates the sampled packet with the path it takes
through the virtual switch. Path information currently includes mangling,
encapsulation and decapsulation actions for tunneling protocols GRE,
VXLAN, Geneve, MPLS and QinQ, but this extension requires no further
changes to accommodate datapath actions that may be added in the
future.

Adding path information enhances visibility into complex virtual
networks.

Signed-off-by: Neil McKee <neil.mckee@inmon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>