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/match.c b/src/match.c
index 741488a..fe1433d 100644
--- a/src/match.c
+++ b/src/match.c
@@ -64,7 +64,7 @@
     }
     if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
     {
-	semsg(_(e_nogroup), grp);
+	semsg(_(e_no_such_highlight_group_name_str), grp);
 	return -1;
     }
     if (pat != NULL && (regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)