RAGFlow go API server (#13240)

# RAGFlow Go Implementation Plan 🚀

This repository tracks the progress of porting RAGFlow to Go. We'll
implement core features and provide performance comparisons between
Python and Go versions.

## Implementation Checklist

- [x] User Management APIs
- [x] Dataset Management Operations
- [x] Retrieval Test
- [x] Chat Management Operations
- [x] Infinity Go SDK

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Yingfeng Zhang <yingfeng.zhang@gmail.com>

internal/cpp/opencc/utils.c

@@ -0,0 +1,36 @@
+/*
+ * Open Chinese Convert
+ *
+ * Copyright 2010 BYVoid <byvoid.kcp@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "utils.h"
+
+void perr(const char *str) { fputs(str, stderr); }
+
+int qsort_int_cmp(const void *a, const void *b) { return *((int *)a) - *((int *)b); }
+
+char *mstrcpy(const char *str) {
+    char *strbuf = (char *)malloc(sizeof(char) * (strlen(str) + 1));
+    strcpy(strbuf, str);
+    return strbuf;
+}
+
+char *mstrncpy(const char *str, size_t n) {
+    char *strbuf = (char *)malloc(sizeof(char) * (n + 1));
+    strncpy(strbuf, str, n);
+    strbuf[n] = '\0';
+    return strbuf;
+}