ovn: use name instead of uuid as key of logical router ports

ovn: use name instead of uuid as key of logical router ports

Before this patch, logical switch ports were using name as key but
logical router ports using uuid, which confuses user when trouble-
shooting, and names of patch ports unreadable. This patch unifies
it by using "name" field also for logical router ports.

Signed-off-by: Han Zhou <zhouhan@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>