(Reuters) -Unilever on Tuesday became the first major European food company to stop imports and exports out of Russia after the country’s invasion of Ukraine. Earlier in the day, Shell said it would stop buying Russian oil, even as Britain said it would ban imports of the commodity by gradually phasing them out during 2022. Other major British consumer firms, including online fashion retailers ASOS and Boohoo as well as food & clothing retailer Marks & Spencer, have also shunned Russia or reduced exposure to the country. The maker of Dove soap and Knorr soup said it would not invest any furthe…