Describe the bug

The page only updates the cost if you look at the page. We'd expect it to change on relevant variables like DC or AC system size

To Reproduce

Steps to reproduce the behavior:

1. Set up a case in SAM using the PV cost curve
2. Duplicate the case
3. Change the system size in the 2nd case
4. The systems have the same total installed cost

Expected behavior

The PV cost curves page should update the system costs any time the typical system costs page would. This likely requires additional on_change functions.