Cleanup k6 test templatters (Split-2)

Cleanup k6 test templatters (Split-2)

- the current template files make the development of k6 test complex and
  difficult to manage unnecessarily, need to be removed
- so that new ports and variables for the kubernetes cluster can be
  provieded easily for Split-3
- simplify the algorith to generate a human readeable summary report
- remove internal nodePort that is a remained action from commit
  (Split-1) that already merged
- total lines of code removed approx: 600

Issue-ID: CPS-2967

Change-Id: I971c58814890a4b65a283bb09411122d0647fd31
Signed-off-by: halil.cakal <halil.cakal@est.tech>