fix: Remove optional params as null in docs

[ksentak]

When generating documentation from the OpenRPC, some methods have optional fields in either the request or response. These fields don't have to be present AT ALL if not needed.

Due to how the tooling is interpreting the schema vs the examples, documentation is being generated that infers that you must pass or receive these fields with "null" as the value instead of having the option to omit them entirely.

This PR fixes the documentation so that null is not passed as the value of an optional parameter that is not used in the examples section for a method.

// Example of what documentation currently looks 
let advertisingId = await Advertising.advertisingId(null)

// What documentation will now look like
let advertisingId = await Advertising.advertisingId()

If a method has multiple optional parameters and there is an example that sets the second optional parameter, undefined will be used as the first parameter.

method(undefined, 'value')