tests: Fix frequent ospfv3 basic functionality test failure

tests: Fix frequent ospfv3 basic functionality test failure

The dead timer is set to 4 seconds, while the hello interval is set to 6535.
This test will only pass of the platform is fast enough for ospfv3 to
converge in 4 seconds. These timers were already tested multiple time earlier.
This test should just make sure that the boundary value 65535 is configurable,

Other changes in this commit:
  - add sequence numbers to the dead intervals tests to make it easier to
    track test faliures.
  - swap the config order in one test to match order with all other tests.

Signed-off-by: Jafar Al-Gharaibeh <jafar@atcorp.com>