new functionality: allow facilities with material losses (path_split) to either lose a portion of whole components or a fraction of each component's mass

[rjhanes]

Follow on from #208

From that issue:

An alternate implementation here would be to use the loss fraction as the probability on a Boolean random variable, and making it so instead of 10% of each component going to landfill, 10% of whole components go to landfill and the rest continue as is. This might be an adjustment to make in the future and would help to capture e.g. window breakage during installation with a little more specificity.