renamed publishDeviceReadRegister() and publishDeviceWriteRegister() into feedDeviceRegisterToControlSystem() and consumeDeviceRegisterFromControlSystem()

renamed publish() and connectToDevice() into more specific feedToControlSystem()/consumeFromControlSyste() and feedToDevice()/consumeFromDevice()

improved structure of network creation and added a FanOut to distribute values to multiple consumers

Introduced the VariableNetwork describing the connections of variables/accessors before things get actually instantiated. This is needed to generate an XML file containing the published variables based on that information.

This is a first mock implementation with very limited functionality. The idea is based on discussions during the OPC-UA control system adapter kickoff meeting and subsequent personal discussions.