Make websocket data handling less sensitive to signal configuration errors
At the moment, the connection to all websockets is "killed" if we attempt to use a component configuration with a wrong signal configuration (wrong number of input or output signals). This behavior should be changed so that the user gets a warning instead and the websocket connections are kept alive.
Also, we should not connect to ICs (websockets) if neither input nor output signals are configured in the component configuration. This may lead to undefined and unexpected behavior.
The changes are especially important for the input widgets that can be tested with the loopback websocket of VILLASnode (if this is set up properly).