feature: add export / import commands to update the config peer's list

[cdxker]

Description

Add CLI commands to export and import user configurations between peers.

Export command:

cli export -o alice.yaml

Generated file format:

threshold:
   t: 5
   n: 3
ip: <system-ipv4>
pubkey: <config-b58-public-key>

Import command:

cli import bob.yaml

Updates the user's config.yaml file with imported settings.

Acceptance Criteria

• Implement export command
• Implement import command
  • import should error if the threshold values do not match