OAuth 1.0 with special chars

[teunlielu]

DO NOT USE ISSUES FOR QUESTIONS

Describe the bug
If you use special characters like: éèç you get error authentication fail.

HttpRequestException: Request failed with status code Unauthorized

To Reproduce

Example code was VB convert to C# for faster responce:
Removed code not important to report the bug.
AddParameter or AddqeuryParameter no difference

` using RestSharp;
using RestSharp.Authenticators;
using RestSharp.Authenticators.OAuth;

internal static partial class Program
{

private const string consumer_key = "*******";
private const string consumer_secret = "*******";
private const string access_token = "*******";
private const string token_secret = "*******";

private const string URL = "https://example.com";

public static void Main(string[] args)
{
    var authenticator = OAuth1Authenticator.ForAccessToken(consumer_key, consumer_secret, access_token, token_secret, OAuthSignatureMethod.HmacSha256);


    var options = new RestClientOptions()
    {
        authenticator = authenticator,
        ThrowOnAnyError = true
    };

    RestResponse response = default;
    RestRequest request = default;

        var client = new RestClient(options);
        request = new RestRequest(URL, Method.Get);
        request.AddParameter("filter", @"éèç");

        request.AddHeader("Content-Type", "application/json");
        response = client.GetAsync(request).Result;
    Console.WriteLine(response.Content);
    Console.ReadKey();
}

} `

Expected behavior
Request returns desired search result

Stack trace
Request failed with status code Unauthorized
at RestSharp.RestClient.d__0.MoveNext()
at RestSharp.RestClientExtensions.d__14.MoveNext()

Desktop (please complete the following information):

• OS: [e.g. Windows 10]
• .NET version [e.g. .NET 6]
• Server to reqeust Linux server.

Additional context
Add any other context about the problem here.

[teunlielu]

It works over Postman.