Scan Message Board for finished DKG Info

[zavgorodnii]

THE PROBLEM (BACKGROUND)

If someone successfully went through the DKG and lost his communication keys and airgapped state, but still has his private bip39 mnemonic, they can not sign any data.

THE SOLUTION (BACKGROUND)

We can scan the topic data for messages from the finished DKG round, provide a mapping from the old communication keys to the new communication keys, build a new Operation for the airgapped machine with both the old messages and the new communication keys — and then process that operation inside the airgapped machine.

THE TASK

Add a client node command that:
— Reads a mapping from the old communication keys to the new communication keys;
— Replaces old communication keys with the new ones inside the FSM;
— Prepares an Operation with the old DKG messages.