Corrections in the Hohlraum testcase

[chinsp]

1. Typo; QoI-2: K and R have the same value
2. Line integral QoI (QoI 5/6) is hard to understand
3. Recolouring of the Hohlraum testcase. Very confusing
4. Typo after equation 26. $G$ is missing in the definition of $W$

[ScSteffen]

comments:
All relates to paper

[chinsp]

1. The definition of QoI5 and QoI6 do not make sense. A_{L} is not the average but just the line integral for each "line through the centre"
2. In QoI 6, the variance formula also needs to be updated. Division by length(L) doesnt make sense. Moreover, there needs to be a summation over different elements.