job_specs: 2n-zn2 reduce number of report coverage tests

Remove:
- All vts tests, obsolete use cases.
- dot1q tests apart from dot1q-l2bd, superfluous combinations.
- nat44 -pps tests, replaced by -tput tests.
- nat44 h1-p1-s1 single session tests, unessential combination.
- nat44 h4096-p63-s258048 tests, non-essential scale combination.

Change-Id: Ia67492b2fd132a64f05a1e8de4cfc136a015fef3
Signed-off-by: Maciek Konstantynowicz <mkonstan@cisco.com>
(cherry picked from commit 58edde117f1c2bd758cb77a6b19fb1e275bcbfe6)