fix(tinyxml2): CVE-2024-50614/50615 - fix integer overflow in char refs

- Use uint32_t instead of unsigned long for UCS values
- Add MAX_CODE_POINT check (0x10FFFF) to prevent overflow
- Remove unnecessary TIXMLASSERT checks that don't prevent overflow

Upstream: leethomason/tinyxml2#1055
Generated-By: uos/glm-5.1
Co-Authored-By: hudeng <hudeng@deepin.org>

Author: deepin-ci-robot