patch 8.2.3961: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/quickfix.c b/src/quickfix.c
index c007a9c..05cae9e 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -7653,7 +7653,7 @@
     // A dict argument cannot be specified with a non-empty list argument
     if (list->lv_len != 0 && what != NULL)
     {
-	semsg(_(e_invarg2),
+	semsg(_(e_invalid_argument_str),
 			 _("cannot have both a list and a \"what\" argument"));
 	return FAIL;
     }
@@ -7780,7 +7780,7 @@
 
     if (buf == NULL)
     {
-	emsg(_(e_invarg));
+	emsg(_(e_invalid_argument));
 	return FAIL;
     }