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Fold algorithms need to be updated to match P2322R5

Fold algorithms need to be updated to match P2322R5: a task in LegoFlow-SWE (Harbor dataset). The C++ standard proposal P2322R5 renames these to: - fold left - fold right - fold left first - fold right last

The task

The C++ standard proposal **P2322R5** renames these to: - `fold_left` - `fold_right` - `fold_left_first` - `fold_right_last`

Part of Lego-X/LegoFlow-SWE.