patch 9.1.0150: Several minor 'winfixbuf' issues

Problem:  several minor 'winfixbuf' issues exist, mostly relating to the
          quickfix list
Solution: address them and adjust tests. Retab and reflow a few things too.
          (Sean Dewar)

Things touched include:

- Replace the semsgs with gettext'd emsgs.

- Handle window switching in ex_listdo properly, so curbuf and curwin
  are kept in-sync and trigger autocommands; handle those properly.

- Don't change the list entry index in qf_jump_edit_buffer if we fail
  due to 'wfb' (achieved by returning FAIL; QF_ABORT should only be used
  if the list was changed).

- Make qf_jump_edit_buffer actually switch to prevwin when using `:cXX`
  commands **outside** of the list window if 'wfb' is set in curwin.
  Handle autocommands properly in case they mess with the list.

  NOTE: previously, it seemed to split if 'wfb' was set, but do nothing
  and fail if prevwin is *valid*. This behaviour seemed strange, and maybe
  unintentional? Now it aligns more with what's described for the `:cXX`
  commands in the original PR description when used outside a list window,
  I think.

- In both functions, only consider prevwin if 'wfb' isn't set for it;
  fallback to splitting otherwise.

- Use win_split to split. Not sure if there was a specific reason for
  using ex_splitview. win_split is simpler and respects modifiers like
  :vertical that may have been used. Plus, its return value can be checked
  for setting opened_window in qf code (technically win_split_ins autocmds
  could immediately close it or change windows, in which the qf code might
  close some other window on failure; it's already the case elsewhere,
  though).

closes: #14142

Signed-off-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/window.c

@@ -167,7 +167,7 @@ check_can_set_curbuf_disabled(void)
 {
     if (curwin->w_p_wfb)
     {
-	semsg("%s", e_winfixbuf_cannot_go_to_buffer);
+	emsg(_(e_winfixbuf_cannot_go_to_buffer));
 	return FALSE;
     }
     return TRUE;
@@ -183,7 +183,7 @@ check_can_set_curbuf_forceit(int forceit)
 {
     if (!forceit && curwin->w_p_wfb)
     {
-	semsg("%s", e_winfixbuf_cannot_go_to_buffer);
+	emsg(_(e_winfixbuf_cannot_go_to_buffer));
 	return FALSE;
     }
     return TRUE;