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/vim9script.c b/src/vim9script.c
index 72c7088..ad0830f 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -83,7 +83,7 @@
     }
     if (!IS_WHITE_OR_NUL(*eap->arg) && STRCMP(eap->arg, "noclear") != 0)
     {
-	semsg(_(e_invarg2), eap->arg);
+	semsg(_(e_invalid_argument_str), eap->arg);
 	return;
     }
     if (si->sn_state == SN_STATE_RELOAD && IS_WHITE_OR_NUL(*eap->arg))
@@ -771,7 +771,7 @@
     // Check for valid starting character.
     if (!eval_isnamec1(*arg))
     {
-	semsg(_(e_invarg2), arg);
+	semsg(_(e_invalid_argument_str), arg);
 	return arg + STRLEN(arg);
     }