[Bug]: max_datagram_frame_size类型不统一，导致溢出

[haojiubujian0]

What happened?

max_datagram_frame_size类型目前存在uint64_t和uint16_t：

typedef struct {
    uint64_t  max_datagram_frame_size;
} xqc_transport_params_t;

typedef struct {
    ...
    uint16_t   max_datagram_frame_size;
} xqc_trans_settings_t;

typedef struct {
    ...
    uint16_t  max_datagram_frame_size;
} xqc_conn_settings_t;

typedef struct {
    ...
    uint16_t max_datagram_frame_size;
} xqc_conn_public_local_trans_settings_t;

typedef struct {
    ...
    uint16_t max_datagram_frame_size;
} xqc_conn_public_remote_trans_settings_t;

当浏览器设置max_datagram_frame_size为65536时，xqc_transport_params_t转换至xqc_conn_settings_t会溢出进而导致判断对端的数据报支持性发生错误（比如conn->remote_settings.max_datagram_frame_size == 0）：

xqc_int_t
xqc_conn_set_remote_transport_params(...)
{
    ...
    /* copy settings from transport parameters */
    xqc_trans_settings_t *settings = &conn->remote_settings;
    ...
    settings->max_datagram_frame_size = params->max_datagram_frame_size;
}

是否统一成uint64_t合适？

Steps To Reproduce

Information and Steps to reproduce the behavior.

Relevant log output