Fix ambiguous overload error with abs
Older compilers (i.e., GCC 6.5) were creating errors when using abs with a double. The compiler was getting confused between the old C abs and the C++ std::abs.
The problem is fixed by specifying the std::abs namespace specifically.
This MR resolves paraview/paraview#21687 (closed).
Backport: release Backport: paraview/release
Edited by Spiros Tsalikis