Processing ClassTypeDef separately in Annotation values

[elifKurtay]

Representing ClassTypeDef as a Class<> in the Annotation values.

Desired usage:

AnnotationDef.builder(ClassTypeDef.of("jackson.annotation.JsonSubTypes.Type"))
                .addMember("value", ClassTypeDef.of("Account"))
                .addMember("name", "string")
                .build()

This PR would generate:

@JsonSubTypes.Type(
            value = Account.class,
            name = "string"
        )

Base branch generates:

@JsonSubTypes.Type(
            value = ClassName[className=Account, nullable=false],
            name = "string"
        )