Support to call C# named parameters from Python #849

Hi,
this is a change request:

Environment

• Pythonnet version: 2.3.0.0
• Python version: 3.6.5 32-bit
• Operating System: Win 10

Details

In a python module, we want to call a C# Method, that has named optional parameters. But these are ignored.
Reason: The MethodBinder.Bind(IntPtr inst, IntPtr args, IntPtr kw, MethodBase info, MethodInfo[] methodinfo) Method ignores the passed python keyword-arguments. But instead, it should assign them to the C# named parameters, if appropriate. Can you extend pythonnet to support named parameters?

snip

• C#

public class LibWithDefault
{
    public static string FuncWithDefault(int x, object b = null)
    {
        return $"x: {x} b: {b} ";
    }
}

• Python

import clr
clr.AddReference("CS_DefaultParam")
from CS_DefaultParam import LibWithDefault
res = LibWithDefault.FuncWithDefault(x=3, b=4)
print(res)