[csharp-netcore] optionalMethodArgument seems not work in csharp*

Description

Hi,
I'm trying to generate a Csharp-netcore client and integrate it with my application.
I'm struggling integrating it with Automapper because of the default parameters.
I read the documentation and saw that there is an option for excluding them "optionalMethodArgument" but regardless of the value I use in the config I always obtain the same result.

openapi-generator version

4.3.0

Command line used for generation

java -jar .\openapi-generator-cli.jar generate -i .\checkoutrestriction.yaml -g csharp-netcore -o solution -c .\config.json

{
"targetFramework":"netstandard2.0",
"optionalMethodArgument":"false",
"validatable":"false",
"netCoreProjectFile":"true"
}

Steps to reproduce

Execute the previous command with optionalMethodArgument set to false over a spec that has required fields.

Suggest a fix/enhancement

I don't know if this is either a bug or an implementation decision, that's what I was trying to find out. Fix/enhancement would be to add this verification to the mustache template I guess.

Start by generating the C# client with checkoutrestriction.yaml and config.json, comparing the output when optionalMethodArgument is set to false. Trace where that option is consumed for the csharp-netcore generator and verify whether required fields are expected to produce optional method arguments. Done means the option's behavior is corrected or clearly established with a reproducible result.