fix: handle empty power samples in total_power() to prevent ZeroDivisionError#1129

wangwangbobo wants to merge 5 commits intomlco2:mastermlco2/codecarbon:masterfrom

wangwangbobo:fix-total-power-zero-divisionwangwangbobo/codecarbon:fix-total-power-zero-divisionCopy head branch name to clipboard