Optimize OPC-UA gateways' address scanning

As many of the PLC's and Yokogawa historian have vasts amounts of tags they expose the address space of their OPC-UA servers is very large. (500.000+ nodes for Yokogawa, at this point unclear how large in total).

The OPC-UA gateway frequently crashes with an OutOfMemoryException during the scanning of the addressspace. For Yokogawa it is not possible to limit the scan to a subset of the addresses due to missing references in the addressspace.

If possible the OPC-UA gateway should try to limit the amount of memory used for scanning the addressspace and try to "stream" the model to its database/storage. This way the OPC-UA gateway should not crash due to the model being constructed eats up all of the memory allocated to the gateway.