fix(ui): ext_cmdline should not move cursor to curwin

Problem:  The ext_cmdline cursor position on the screen seems to rely on
          an implicit assumption that the event listener implements a
          cmdline window that is made the current window which is
          problematic (e.g. breaks 'incsearch' in the actual current
          window).
Solution: Remove this assumption and allow nvim_win_set_cursor() to move
          the cursor on the screen to a non-current window (previous
          commit).

src/nvim/ex_getln.c

@@ -767,7 +767,7 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
   }
 
   setmouse();
-  ui_cursor_shape();               // may show different cursor shape
+  setcursor();
 
   TryState tstate;
   Error err = ERROR_INIT;
@@ -927,7 +927,6 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
   }
   may_trigger_modechanged();
   setmouse();
-  ui_cursor_shape();            // may show different cursor shape
   sb_text_end_cmdline();
 
 theend:
@@ -3859,7 +3858,6 @@ void cursorcmd(void)
     if (ccline.redraw_state < kCmdRedrawPos) {
       ccline.redraw_state = kCmdRedrawPos;
     }
-    setcursor();
     return;
   }
 
@@ -4553,6 +4551,7 @@ static int open_cmdwin(void)
   State = save_State;
   may_trigger_modechanged();
   setmouse();
+  setcursor();
 
   return cmdwin_result;
 }