patch 8.2.3190: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move error messages to errors.h and give them a clear name.
diff --git a/src/edit.c b/src/edit.c
index d944080..5280a82 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -2874,7 +2874,7 @@
     ptr = get_last_insert();
     if (ptr == NULL)
     {
-	emsg(_(e_noinstext));
+	emsg(_(e_no_inserted_text_yet));
 	return FAIL;
     }