patch 8.2.0747: cannot forcefully close all popups

Problem:    Cannot forcefully close all popups.
Solution:   Add the "force" argument to popup_clear().  Use it after running a
            test.  Put back the check for a popup when editing a file.
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 0147e68..4fa3013 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -34,9 +34,9 @@
 void f_popup_show(typval_T *argvars, typval_T *rettv);
 void f_popup_settext(typval_T *argvars, typval_T *rettv);
 int error_if_popup_window(int also_with_term);
-int popup_close(int id);
-int popup_close_tabpage(tabpage_T *tp, int id);
-void close_all_popups(void);
+int popup_close(int id, int force);
+int popup_close_tabpage(tabpage_T *tp, int id, int force);
+void close_all_popups(int force);
 void f_popup_move(typval_T *argvars, typval_T *rettv);
 void f_popup_setoptions(typval_T *argvars, typval_T *rettv);
 void f_popup_getpos(typval_T *argvars, typval_T *rettv);