NYAHURURU, Kenya — This Valentine’s Day, there’s a good chance your flowers came from Kenya.“I know the flowers are for giving on Valentine’s Day,” said Phanice Cherop, a worker at a flower farm in Kenya. “They are very beautiful.”On a crisp February morning, Cherop squeezed through a row of shoulder-high white roses, cut a flower and methodically placed it in the bunch she carried. The Kenyan-grown flower was likely headed for a vase in Australia, England, Japan or the …