patch 8.2.4911: the mode #defines are not clearly named

Problem:    The mode #defines are not clearly named.
Solution:   Prepend MODE_.  Renumber them to put the mapped modes first.
diff --git a/src/charset.c b/src/charset.c
index 657ab85..6fd8b6b 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1300,7 +1300,7 @@
     if (cursor != NULL)
     {
 	if (*ptr == TAB
-		&& (State & NORMAL)
+		&& (State & MODE_NORMAL)
 		&& !wp->w_p_list
 		&& !virtual_active()
 		&& !(VIsual_active