Correct the entry point in the `losscalculator`

After implementation of this comment, now we can run damage and loss computations as below:
damagecalculator damage [input parameters]
losscalculator loss [input parameters]

But to have a coherent command, we want to be able to execute the commands as below:
losscalculator loss/damage/fatalities [input parameters]
which should be done in this MR

Although in this case, we may want to rename the losscalculator to correctly indicate that it does not only compute losses, but also damage.