Organize Subsets when Changing Applies To Section in Blueprint mode

[jmancuso]

As a user, it would be nice to have the subsets indented under their parent lists when changing the applies to section in a module blueprint mode. This organization would mirror the same organization shown when adding dimensions in the initial module creation.  This would decrease the time spent finding a subset, especially when using a model that has many subsets. Currently the sorting of the subsets in this window is difficult to navigate and not intuitive for users that I've spoken to.

[nick_barker]

I think this is a very sensible idea as currently it is a time consuming process finding the correct subset. Obviously following best practices I have named them correctly but then they are not grouped together alphabetically at the bottom of the list either.