net: fou: use policy and operation tables generated from the spec

Generate and plug in the spec-based tables.

A little bit of renaming is needed in the FOU code.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>