Mulighet for å endre knapp i summary2-komponent dersom logikk i skjema endres

### Description

Ønske om å kunne endre visning til "neste"-knapp i stedet for "tilbake til oppsummering"-knapp dersom man går tilbake og endrer valg/annen radiobutton i skjema og dermed ikke skal tilbake til den samme oppsummeringen.

### Additional Information

_No response_

Start by locating the Summary2 component and the navigation logic that chooses between the “next” and “back to summary” buttons; reproduce returning to the form and changing a radio-button choice. Done means the button shows “next” when the form state no longer leads to the same summary, while retaining the existing back behavior otherwise.

Written by the indexing model from the issue text.