同一个container接连打开两个返回结果的原生页面，第二次打开的页面接收不到结果

场景：
假设有一个flutter页面A，两个原生页面B和C。

A页面打开B页面，在B页面返回的结果中继续打开C页面。

BoostNavigator.instance.push(
‘B',
withContainer: true,
arguments: {},
opaque: true,
).then((dynamic result) {
// 能正常返回
flutterLog("flutterboost.resultHandler: result.B: $result");

// 返回结果中打开C页面
BoostNavigator.instance.push(
‘C',
withContainer: true,
arguments: {},
opaque: true,
).then((dynamic result) {
// 一打开C页面，该回调立马执行，返回null。
flutterLog("flutterboost.resultHandler: result.C: $result");
});

});

经过源码定位，发现是下面代码导致：

void onContainerShow(CommonParams params) {
final container = _findContainerByUniqueId(params.uniqueId)!;
BoostLifecycleBinding.instance.containerDidShow(container);

// Try to complete pending native result when container closed.
final topPage = topContainer?.topPage.pageInfo.uniqueId ?? "";
assert(topPage != null);
Future.delayed(
const Duration(seconds: 1),
() => _completePendingNativeResultIfNeeded(topPage),
);
}

void _completePendingNativeResultIfNeeded(String initiatorPage) {
_pendingResult.keys
.where((element) => element.startsWith('$initiatorPage#'))
.toList()
.forEach((key) {
_pendingResult[key]!.complete();
_pendingResult.remove(key);
Logger.log('_completePendingNativeResultIfNeeded, '
'key:$key, size:${_pendingResult.length}');
});
}

这里在容器显示时，延迟1秒读取上一个页面返回的数据，并且从_pendingResult中移除了当前容器。

修改建议：
如果发现打开了另一个页面，是否考虑取消延迟事件_completePendingNativeResultIfNeeded。

Reproduce the A→B→C navigation sequence described in the issue and inspect onContainerShow and _completePendingNativeResultIfNeeded, especially the delayed one-second completion and _pendingResult removal. Confirm why opening C completes its callback with null, then verify that the B result remains correct and C receives its own result after the fix.

Written by the indexing model from the issue text.