TASK: Remove doctrine/orm dependency
TASK: Remove doctrine/orm dependency

As the doctrine classes are only used for type checks in
``instanceof`` and ``is_subclass_of`` and both work with
non existing classes we can drop the dependency on
``doctrine/orm`` in this package.

aertmann/flow-development-collection,kdambekalns/flow-development-collection,bwaidelich/flow-development-collection,bwaidelich/flow-development-collection,daniellienert/flow-development-collection,neos/flow-development-collection,neos/flow-development-collection,daniellienert/flow-development-collection,robertlemke/flow-development-collection,daniellienert/flow-development-collection,chewbakartik/flow-development-collection,albe/flow-development-collection,mkeitsch/flow-development-collection,gerhard-boden/flow-development-collection,robertlemke/flow-development-collection,albe/flow-development-collection,fcool/flow-development-collection,neos/flow-development-collection,aertmann/flow-development-collection,neos/flow-development-collection,fcool/flow-development-collection,robertlemke/flow-development-collection,dlubitz/flow-development-collection,fcool/flow-development-collection,dlubitz/flow-development-collection,fcool/flow-development-collection,bwaidelich/flow-development-collection,mkeitsch/flow-development-collection,kdambekalns/flow-development-collection,chewbakartik/flow-development-collection,aertmann/flow-development-collection,albe/flow-development-collection,gerhard-boden/flow-development-collection,dlubitz/flow-development-collection,kdambekalns/flow-development-collection,kdambekalns/flow-development-collection,robertlemke/flow-development-collection,chewbakartik/flow-development-collection,gerhard-boden/flow-development-collection,mkeitsch/flow-development-collection