tests: add fuzz setup.

tests/fuzz/sql-fuzzer.c

+#include "qSqlparser.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size){
+    char *new_str = (char *)malloc(size+1);
+    if (new_str == NULL){
+        return 0;
+    }
+    memcpy(new_str, data, size);
+    new_str[size] = '\0';
+
+    qSqlParse(new_str);
+
+    free(new_str);
+    return 0;
+}