Use primary identifiers as device registry keys

[johanstokking]

Summary:

Use primary identifiers as keys in Join Server while keeping EUIs unique.

Why do we need this?

To do device management with primary identifiers, but lookup of join-request by EUIs.

What is already there? What do you see now?

• Database key is EUI
• Device registry needs the EUIs as part of the given end device identifiers, but in a GET these are not available through the gRPC gateway

What is missing? What do you want to see?

• Use primary identifiers as database key
• Use EUI key pointing to the primary identifiers

Basically the same functionality as in NS.

How do you propose to implement this?

Copy NS functionality.

What can you do yourself and what do you need help with?

Will do.

[johanstokking]

Will be merged with #194