[cleanup] Reorder loops in TestEvaluate

Currently the evaluation of the differential quotient is done for any shape function again. Since our interface does bulk-evaluation of all shape functions at once, we effectively evaluate at the same position n-times, where n is the number of shape functions.

This commit reorders the loops such that we only loop over all shape functions in one of the inner loops and avoid this problem. For a non-optimized build of testgerericfem this reduces the runtime by ~25%.

Most of the diff is whitespace changes.