[North] - Display data sources in North display

[burgerni10]

Show on the Nord display screen from which sources data are received. It can be from South connectors and external sources.
Be sure to show only south connectors that send data compatible with the North connector.

For example, OPCUA sends JSON values, not compatible with Azure Blob (file only). This connector shouldn't be displayed as a source, even if subscribed by the Aure Blob Connector