Generator: Add ability to filter by operation and/or type

[macghriogair]

Given a large WS definition, with hundreds of operations where one would want to use only a subset, it might be useful to provide a configuration option to the generate command to consider only specific types or types referenced by an operation. I have in mind something similar this package offers: https://github.com/wsdl2phpgenerator/wsdl2phpgenerator#operationnames

In my usecase the generation results in 3000+ classes and 8000+ metadata files. Since it's generated code, and for the sake of auto-completion, maybe I should not care and just commit everything to vcs? On the otherhand, I am able to tell apart which methods I will use. A workaround might be to shorten the wsdl/xsd manually but that seems hacky.

[victorgp89]

Do you resolve this problem?