[PostSharedBufferToScript] Ensure Web receives the Buffer

Is your feature request related to a problem? Please describe.

Currently, PostSharedBufferToScript does not ensure that the web has received the buffer. We manually have to post a message from the web once we receive the buffer.
I have faced cases where I posted the buffer but it was not yet received by the web counterpart resulting in a failure.
So, I use the following core as of now to ensure everything works fine:

        private readonly Dictionary<long, TaskCompletionSource<object>> _sharedBufferReceivedGuarantor = new();

        internal SharedBufferManager(WebView2 webView2)
        {
            _webView2 = webView2;
            _webView2.WebMessageReceived += OnMessageReceivedFromWeb;
        }

        private void OnMessageReceivedFromWeb(WebView2 sender, CoreWebView2WebMessageReceivedEventArgs args)
        {
            if (!long.TryParse(args.WebMessageAsJson, out var id) || !_sharedBufferReceivedGuarantor.ContainsKey(id))
            {
                return;
            }

            var tcsThatCanBeResolved = _sharedBufferReceivedGuarantor[id];
            _sharedBufferReceivedGuarantor.Remove(id);
            tcsThatCanBeResolved.SetResult(null);
        }


        private async Task GuaranteeSharedBufferIsPostedToScript(
            CoreWebView2SharedBuffer sharedBuffer, CoreWebView2SharedBufferAccess access, long id)
        {
            var tcs = new TaskCompletionSource<object>();
            _sharedBufferReceivedGuarantor.Add(id, tcs);

            _webView2.CoreWebView2.PostSharedBufferToScript(
                sharedBuffer, access, $"{{\"id\":{id}}}");

            await tcs.Task;
        }

const sharedBufferReceivedHandler = e => {
  // ...
  chrome.webview.postMessage(e.additionalData.id)
}

chrome.webview.addEventListener('sharedbufferreceived', sharedBufferReceivedHandler)

Describe the solution you'd like and alternatives you've considered

It would be good to ensure this internally. The implementation could be similar to what I am using.

AB#43932527