patch 8.2.3975: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 604114c..e612505 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -4982,8 +4982,7 @@
 
     // Can't use emsg() here, we have not finished initialisation yet.
     vim_snprintf(buf, IOSIZE,
-	    _("E243: Argument not supported: \"-%s\"; Use the OLE version."),
-	    arg);
+			 _(e_argument_not_supported_str_use_ole_version), arg);
     mch_errmsg(buf);
 }
 #endif
@@ -8682,7 +8681,7 @@
 
     if (mesg != NULL && mesgCB != NULL)
     {
-	iemsg(_("E232: Cannot create BalloonEval with both message and callback"));
+	iemsg(_(e_cannot_create_ballooneval_with_both_message_and_callback));
 	return NULL;
     }