port: Add support for search invoke (#6272) #1458

The changes in Add support for search invoke (#6272) may need to be ported to maintain parity with microsoft/botbuilder-dotnet.

Fixes #5643

OnInvokeActivityAsync here:
https://github.com/OfficeDev/Microsoft-Teams-Samples/blob/main/samples/bot-type-ahead-search-adaptive-cards/csharp/TypeaheadSearch/Bots/ActivityBot.cs#L85

Would be changed to:

protected override async Task<SearchInvokeResponse> OnSearchInvokeAsync(ITurnContext<IInvokeActivity> turnContext, SearchInvokeValue invokeValue, CancellationToken cancellationToken)
{
    var packageResult = JObject.Parse(await(new HttpClient()).GetStringAsync($"https://azuresearch-usnc.nuget.org/query?q=id:{invokeValue.QueryText}&prerelease=true"));
    if (packageResult == null)
    {
        // no results available, return 204
        return new SearchInvokeResponse
        {
            Type = "application/vnd.microsoft.search.searchResponse",
            StatusCode = 204
        };
    }
    else
    {
        var packageList = packageResult["data"]
            .Skip(invokeValue.QueryOptions.Skip)
            .Take(invokeValue.QueryOptions.Top)
            .Select(item => (item["id"].ToString(), item["description"].ToString()))
            .Select(item => new { title = item.Item1, value = item.Item1 + " - " + item.Item2 })
            .ToList();
        
        return new SearchInvokeResponse
        {
            Type = "application/vnd.microsoft.search.searchResponse",
            Value = JObject.FromObject(new { results = packageList }),
            StatusCode = 200
        };
    }
}

Please review and, if necessary, port the changes.