Returns the device’s unique ID as a string
DEPRECATED METHOD — DO NOT USE IN NEW CODE
This method returns the device's unique id, as a string. It is deprecated because the same information is also available as hardware.getdeviceid(), which is a less confusing name.
Although this method is deprecated, removing it altogether might cause users' existing code to stop working so we currently have no plans to do so. However, this method has been removed from the imp005 and imp004m. Calling this method rather than hardware.getdeviceid() on this hardware will trigger a runtime error.