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/cindent.c b/src/cindent.c
index 57add39..dc9c203 100644
--- a/src/cindent.c
+++ b/src/cindent.c
@@ -2114,7 +2114,7 @@
     // inserting new stuff.
     // For unknown reasons the cursor might be past the end of the line, thus
     // check for that.
-    if ((State & INSERT)
+    if ((State & MODE_INSERT)
 	    && curwin->w_cursor.col < (colnr_T)STRLEN(linecopy)
 	    && linecopy[curwin->w_cursor.col] == ')')
 	linecopy[curwin->w_cursor.col] = NUL;