ofproto-dpif-ipfix: add interface Information Elements to flow key

ofproto-dpif-ipfix: add interface Information Elements to flow key

Extend flow key part of data record to include following Information Elements:
- ingressInterface
- ingressInterfaceType
- egressInterface
- egressInterfaceType
- interfaceName
- interfaceDescription

In case of input sampling we don't have information about egress port.
Define templates depending not only on protocol types, but also on flow
direction. Only egress flow will include egress information elements.

With this change, dpif_ipfix_exporter stores every port in hmap rather
than only tunnel ports. It allows to easily retrieve required
information about interfaces during sampling upcalls.

Co-authored-by: Michal Weglicki <michalx.weglicki@intel.com>
Signed-off-by: Michal Weglicki <michalx.weglicki@intel.com>
Signed-off-by: Przemyslaw Szczerbik <przemyslawx.szczerbik@intel.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>