patch 9.0.0917: the WinScrolled autocommand event is not enough

Problem:    The WinScrolled autocommand event is not enough.
Solution:   Add WinResized and provide information about what changed.
            (closes #11576)
diff --git a/src/mouse.c b/src/mouse.c
index 32407eb..b83523a 100644
--- a/src/mouse.c
+++ b/src/mouse.c
@@ -1171,7 +1171,7 @@
 	    leftcol = 0;
 	do_mousescroll_horiz((long_u)leftcol);
     }
-    may_trigger_winscrolled();
+    may_trigger_win_scrolled_resized();
 }
 
 /*