Update ICOc User Interface Text & API Text for New Sensory Milling Hardware

[sanssecours]

Description

Currently ICOc assumes that a (Bluetooth) sensor device is always a sensory tool holder (STH) or sensory holder assembly (SHA). Since we added new hardware (Sensory Milling Head) that is neither, we should make sure that the code, and user interface reflects these changes:

• Use “sensor device” or “device” everywhere we used the term “STH” or SHA” in the user interface; While ideally the description should include the name of the actual hardware e.g. ”SMH” or “STH” we have no way to distinguish these devices in software yet.
• Replace the term sth in the API with device or sensor_device; One example for such a function would be connect_sth in the Network class.
• Update the documentation for the new hardware