Remember user selection of the alteration tables in patient view

[zhx828]

If we could remember what columns the user selected to visualize would be very helpful. It does not need to persist all the time, but at lease within the same session would be super helpful.

The use case is that when I reviewing a list of samples/patients using the navigation buttons, https://www.cbioportal.org/patient?studyId=msk_impact_2017&caseId=P-0000377#navCaseIds=msk_impact_2017:P-0000377,msk_impact_2017:P-0001104,msk_impact_2017:P-0004910 as an example, I would select additional columns for my analysis. I would want to see the additional columns that I selected to be shown then jumping through cases.