The connection handler in websocket transport was not using the
'UserAuthentication' interface to resolve user info. Fix resolving
user info in websocket transport to use the common
'UserAuthentication' interface
* remove phase one/two distinction and hdbquery typeclass
* move extensions to default-extensions
* switch to LazyTx which only acquires a connection if needed
* move defns from TH module into Ops module
* remove tojson orphan instance for http exception
* remove orphan instance for dmlp1
* getTopLevelNodes will not throw any exceptions
