Back btn from delegate page should remember scroll position

[dnlklmn]

when going back from the delegate page you always end up on the top of the page
this is confusing especially when you check details of a delegate after picking the tracks, and you have to scroll all the way down again to continue

note that i've added a scroll to top (ScrollToTop) function to DelegationLayout.tsx to end up on the top of the delegate page independent of where you got there from