data: add webservice type config

Unlike the jobs framework, toolforge-webservice needs to know how to start a web service for a given image. For this we add a 'wstype' extra property to the web service images, which directly match with existing classes in toolsws.wstypes in the webservice source code.

JVM images also get a flag that they are based on JVM and should have extra memory by default. This is to match current behaviour on toolforge-webservice.