Discovered while working on https://github.com/vercel/next.js/pull/14848

when asPath is the same but href is different it should use `replaceState` instead of `pushState`, so that browser back/forward behavior is preserved. Currently it's comparing a path that includes basepath with one that excludes  it, so `pushState` is always used. This makes sure the behavior is the same as when running next.js without a basepath