Removes method set_packet_handler_closure() from EvdJsonFilter

This is was never used and is no longer necessary.
Adds destroy notify arg for @user_data to set_packet_handler() of EvdJsonRpc

Also removes the internal packet handler GClosure and use the provided callback
directly.
Adds annotations to evd_websocket_protocol_bind()
Adds destroy notify args to set_transport_(pull/push)_func() of EvdTlsSession
Adds destroy notify argument to set_cert_callback() of EvdTlsCredentials
Adds destroy notify argument to add() method of EvdPoll
Adds annotations to import_native() methods of EvdPkiPrivkey and EvdPkiPubkey