Unable to use the string '%2F' in a url parameter

[cg-finbourne]

Describe the bug
We need to use parameters with the characters '%2F' in them. After the change to src/RestSharp/Parameters/Parameter.cs in 4ddda24, which changed the Value property of the Parameter record from having an init set accessor to having no set accessor, we are unable to do this since there is no way to override the regex logic performed on the value in the UrlSegmentParameter constructor. Previously we were doing the following to set the Value property to the desired value

var paramValue = "foo%2fbar";
var param1 = new UrlSegmentParameter("foo", paramValue);
Console.WriteLine(param1); // outputs foo=foo/bar (undesired)
var param2 = param1 with {Value = paramValue};
Console.WriteLine(param2); // outputs foo=foo%2fbar (desired)

We are unable to use a different class for this parameter due to this line https://github.com/restsharp/RestSharp/blob/dev/src/RestSharp/Request/UriExtensions.cs#L57

To Reproduce
Steps to reproduce the behavior, preferably using a code snippet.
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See that this code does not compile:

new UrlSegmentParameter("foo", "foo%2fbar") { Value = "foo%2fbar" };

and new UrlSegmentParameter("foo", "foo%2fbar") results in a parameter with a Value of foo/bar

Expected behavior
A clear and concise description of what you expected to happen.
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We should be able to use a path parameter that includes '%2F' or '%2f'. I have a pull request for a suggested fix here #2265

Stack trace
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Desktop (please complete the following information):

• OS: [e.g. macOS]
• .NET version [e.g. .NET 6]
• Version [e.g. 110.2.0]

macOS .NET 8

Additional context
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[alexeyzimarev]

Why do you encode the parameter value? RestSharp will do it for you. Have you tried providing plain-text value instead?

[cg-finbourne]

Why do you encode the parameter value? RestSharp will do it for you. Have you tried providing plain-text value instead?

we have a use case where the path parameter needs to contain the sequence '%2F' literally, which when encoded will be '%252F'.

As an example:

'/foo/bar/test%252Ftest' is what we want to end up calling, rather than '/foo/bar/test%2Ftest' or '/foo/bar/test/test'