[Java generator] Generate various overloads for functions when some arguments are optional

Assume you have an endpoint search with arguments:

• searchString - required

Java generator will generate something like:

public SearchPreview search(String searchString)

When I add an optional argument int limit to the endpoint, the Java generator will generate

public SearchPreview search(String searchString, int limit)

All the clients using the original search(String searchString) will no longer work. They will have to change their code to use the new function because swagger generator does not generate a search overload without the optional parameters.

It would be great if both methods would be available:

public SearchPreview search(String searchString)
public SearchPreview search(String searchString, int limit)

Start in the Java generator's method-generation path and trace how endpoint arguments become generated client methods. Confirm the behavior for an endpoint with one required and one optional argument; done means both the original single-argument overload and the overload including the optional argument are generated.