fix(api/buffer): fix handling of viewport of non-current buffer

A lot of functions in move.c only worked for curwin, alternatively
took a `wp` arg but still only work if that happens to be curwin.

Refactor those that are needed for update_topline(wp) to work
for any window.

fixes #27723
fixes #27720

src/nvim/state.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "nvim/state_defs.h"  // IWYU pragma: keep
+#include "nvim/types_defs.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "state.h.generated.h"