Support optional parameters in step bindings

[304NotModified]

Would be cool if we support optional parameters, e.g.

[Given(@"Add two numbers (.*) (.*) (.*)")]
[Given(@"Add two numbers (.*) (.*)")] 
public void Testtheconditionwith(string a, string b, string c = null)
{

}

From https://stackoverflow.com/questions/65853669/how-to-accommodate-specflow-step-definition-to-accept-deferent-number-of-paramet

See also #509

[304NotModified]

I did a small POC, I think this has to be done for this:

• Update the engine, see my POC: POC optional parameters in step bindings #511
• Update the VS2022 plugin: https://github.com/reqnroll/Reqnroll.VisualStudio/blob/3555492e4410f15daa2973436b5520000dc4fb75/Reqnroll.VisualStudio/Discovery/ProjectStepDefinitionBinding.cs#L60
• Update the Rider plugin
• Update the docs https://docs.reqnroll.net/latest/automation/step-definitions.html, see also Improve docs about step parameters #508

[clrudolphi]

Will need to consider impacts to steps that accept DataTables or DataStrings as input (as the last parameter), and those that depend upon use of a StepArgumentTransformer.