Support Parameterized Types in Methods

[Sgitario]

This pull request handles the support of parameterized types when creating methods. Example:

public List<String> methodName() {
}

Where List<String> is a parameterized type.

In order to do this, we need to amend the signature of the method as the descriptor does not support it (it says class not found when trying to declare Ljava.util.List<Ljava.lang.String;>;).

In order to resolve this, we have added a wrapper type ParameterizedClass where we can specify the wrapper type and the param types. Usage:

MethodCreator method = creator.getMethodCreator("methodName", new ParameterizedClass(List.class, String.class));

This pull request partially resolves: #66 (which is intended to be for classes too)
Moreover, these changes are inspired by the changes in quarkusio/quarkus#26074 (that there will be deprecated once gizmo dependency is bumped).

I've verified these changes in Quarkus upstream too (reverting the changes of the mentioned Quarkus pull request) and it worked fine.

[mkouba]

So the MethodCreator implements the SignatureElement and allows you to set the method signature. I think that it would be more convenient to provide a signature util method that would accept jandex org.jboss.jandex.Type params.
Maybe something like:

public static String signatureFrom(Type returnType, String methodName, Type[] parameters) {
  // ...
}

declated on the io.quarkus.gizmo.SignatureElement.

Also it seems that ParameterizedClass does not support nested params, or?

[mkouba]

FTR I'm working on a pull request that introduces a SignatureBuilder API (inspired by ideas/work from @Ladicek).

[Sgitario]

Ok, closing.