[BUG]-Endpoints registered to improper parent device fail as an unknown device type

[TrevorPayne]

Describe the bug

When you attempt to register a device to an improper parent, the device registration failure reason is for unknown device type. This ambiguous and makes it difficult to track down issues

Stacktrace

Include a stack trace of the exception if possible.

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To Reproduce Steps to reproduce the behavior: Attempt to load a DM Transmitter device registered to a key that does not exist.

Expected behavior The error should read that the device has nothing to register to, not that it's an unknown device type

Screenshots

Additional context Discovered by client