Kirill Ivanov

Allow to use HttpClient instead of HttpWebRequest

11

## Summary HttpWebRequest produces performance issues. Take a look at these articles for more information: - https://josef.codes/you-are-probably-still-using-httpclient-wrong-and-it-is-destabilizing-your-software/ - https://makolyte.com/csharp-switch-from-using-httpwebrequest-to-httpclient/ - https://www.aspnetmonsters.com/2016/08/2016-08-27-httpclientwrong/ Proposed changes: - Allow passing user's `HttpClient` that could...