Remove device name override

[callumforrester]

With the merging of #147, any object with a property called name can be considered a device, where before some objects without that property could. It no longer makes sense to allow overriding the name in the BlueskyContext, the value of obj.name can be a universal identifier for the object.

[tpoliaw]

Not all devices have names (something that implements Stoppable would be accepted but doesn't have to have a name. I think for now the override isn't a bad idea.