making future om lists easier to use

[k-doering-NOAA]

I think there could be some ways to make future om lists more user friendly.

I think it might be helpful to allow users to put in extra info than needed for cuustom future om lists, as there may be times when users decide to run less iterations or less years. This would allow them to do so without needing to change the custom list.

It would also be helpful if users were able to put "all" for the iterations they want to apply values to, and SSMSE could expand it to all iterations for the given scenario.

We could also do something similar for the model change lists, where changes that are beyond the end year of the simulation are simply ignored (this may already happen, not sure)...