User info queries

int rtc_get_users_info(void* handle, rtc_user_info_t** users, int* count);

rtc_user_info_t* users = NULL;
int count = 0;

if (rtc_get_users_info(rtc, &users, &count) == RTC_OK) {
    printf("Online users: %d\n", count);
    for (int i = 0; i < count; i++) {
        printf("- %s (%s), device type=%d, audience=%d, published tracks=%d\n",
               users[i].uid, users[i].name,
               users[i].device_type, users[i].is_audience,
               users[i].stream_track_count);

        // Iterate over the tracks this user has published
        for (int j = 0; j < users[i].stream_track_count; j++) {
            rtc_track_info_t* t = &users[i].stream_tracks[j];
            printf("    %s [%s] %s\n", t->track_id,
                   t->kind == 0 ? "audio" : "video",
                   rtc_codec_to_string(t->codec));
        }
    }
    rtc_free_users_info(users, count);   // You must pass count back
}

void rtc_free_users_info(rtc_user_info_t* users, int count);

int rtc_get_user_info(void* handle, const char* uid, rtc_user_info_t* user);

rtc_user_info_t user;
if (rtc_get_user_info(rtc, "user123", &user) == RTC_OK) {
    printf("%s / %s / channel=%s / sid=%s\n",
           user.uid, user.name, user.channel, user.sid);
    rtc_free_user_info(&user);   // The struct itself is on the stack; this frees the dynamic memory inside it
} else {
    printf("User doesn't exist\n");
}

void rtc_free_user_info(rtc_user_info_t* user);

int rtc_get_local_user_info(void* handle, rtc_user_info_t* user);

int rtc_get_channel_info(void* handle, rtc_channel_info_t* info);
void rtc_free_channel_info(rtc_channel_info_t* info);