使用WKWebView打开itunes链接无法跳转至AppStore

在UIWebView上，不需要特殊处理直接加载 itunes 链接是可以直接跳转至AppStore的。

NSURL *URL = [NSURL URLWithString:@"https://itunes.apple.com/cn/app/id1013277346?mt=8"];
NSURLRequest *request = [NSURLRequest requestWithURL:URL];
    
self.webView = [UIWebView new];
self.webView.delegate = self;
[self.webView loadRequest:request];

但是，在WKWebView上则不行，需要在navigationDelegate中拦截，手动openURL才能跳转至AppStore。

- (void)loadWithWKWebView
{
    NSURL *URL = [NSURL URLWithString:@"https://itunes.apple.com/cn/app/id1013277346?mt=8"];
    NSURLRequest *request = [NSURLRequest requestWithURL:URL];
    
    self.wkWebView = [WKWebView new];
    self.wkWebView.navigationDelegate = self;
    [self.wkWebView loadRequest:request];
}

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
{
    WKNavigationActionPolicy policy = WKNavigationActionPolicyAllow;
    /* 简单判断host，真实App代码中，需要更精确判断itunes链接 */
    if ([[navigationAction.request.URL host] isEqualToString:@"itunes.apple.com"] &&
        [[UIApplication sharedApplication] openURL:navigationAction.request.URL])
    {
        policy = WKNavigationActionPolicyCancel;
        
    }
    
    decisionHandler(policy);
}

难以理解为啥WKWebView上不支持跳转至AppStore。
如果不处理，普通网页上链接至itunes的，点击后都无法跳转了。