* Update RestSharp to v108
* Add OAuth2 Application (client_credentials) authentication
* Run generators and fix typos
* Undo accidental python and rust changes
* Add documentation, fix authenticator bug, and fix user agent bug
* Fix tests
Missed some changes in the mustache templates.
Also had to update the `netcoreapp2.0` test project to `netcoreapp3.1` for compatibility with RestSharp
* Switch HttpUtility to WebUtility for compatibility