Rename prefix sum methods in vectors to scan
PrefixSum class was renamed to
Scan, but the methods in vector classes (
DistributedVectorView) stayed as
segmentedPrefixSum - see e.g. https://mmg-gitlab.fjfi.cvut.cz/gitlab/tnl/tnl-dev/blob/develop/src/TNL/Containers/Vector.h#L269
While we're renaming things,
exclusiveScan method should be added as a shortcut for
vector.template scan< TNL::Containers::Algorithms::ScanType::Exclusive >(). Both methods should be used in the tutorial.