patch 8.2.3985: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/normal.c b/src/normal.c
index 79e47a6..cd9b0a9 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -3080,7 +3080,7 @@
 		    deleteFold((linenr_T)1, curbuf->b_ml.ml_line_count,
 								 TRUE, FALSE);
 		else
-		    emsg(_("E352: Cannot erase folds with current 'foldmethod'"));
+		    emsg(_(e_cannot_erase_folds_with_current_foldmethod));
 		break;
 
 		// "zn": fold none: reset 'foldenable'