To be used in StressBC which gets improved results for q<0.5. q=0.5 still set as default argument for all other BCs

Tagged fluid nodes where only removed from fluidNodeIndices. If tagged nodes conincided with border nodes the collision was valled twice for these nodes. Nodes lying on the border are now removed from the lists of tagged nodes.

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#con1-by-default-make-objects-immutable

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