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/ex_cmds.c b/src/ex_cmds.c
index f38bdac..9c55de3 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -2484,6 +2484,11 @@
     int		did_inc_redrawing_disabled = FALSE;
     long        *so_ptr = curwin->w_p_so >= 0 ? &curwin->w_p_so : &p_so;
 
+#ifdef FEAT_PROP_POPUP
+    if (ERROR_IF_TERM_POPUP_WINDOW)
+	return FAIL;
+#endif
+
     if (eap != NULL)
 	command = eap->do_ecmd_cmd;
     set_bufref(&old_curbuf, curbuf);