This was not working, as kernelNeedsFluidNodeIndicesToRun is used before
creating the kernel. I still don't like the current solution.

This reverts commit 273156ba.

for better usability --> autocomplete

change the datatype of the variable numberOfNodes aka numberOfLBnodes (fka size_Mat) to unsigned long long ... with respect to large grids (>100e^6 Nodes per Level) ... in this regard the 27 directions are changed to size_t and some control variables are also changed to size_t