ethdev: add missing items/actions to flow object converter

ethdev: add missing items/actions to flow object converter

Several pattern items and actions were never handled by rte_flow_copy()
because their descriptions were missing. rte_flow_conv() inherited this
deficiency.

This patch adds them and reorders others to match rte_flow.h. It doesn't
pose as a fix because so far no one has complained about it and
rte_flow_conv() would have to be backported as well: this function is
the only sane approach to handle VXLAN and NVGRE encap definitions.

As a matter of fact, it's the last missing piece to finally allow
testpmd users to request the creation of VXLAN/NVGRE encap/decap flow
rules without getting rejected outright.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>