[WIP] use the new doctrine compiler pass to map the model classes directly

this is to show how we would use the compiler pass of the doctrine bundle to map our model classes directly.

for now only done for the orm, i will do it for mongo and couch once the pr on doctrine bridge is good to go.

we probably should add a copy of the compiler pass to this bundle for now, until there is a version of doctrine-bundle out that we can say is the minimal version we are compatible with.