* Adds management, signal, and relay (STUN/TURN) health probes to the status command.
* Adds a reason when the management or signal connections are disconnected.
* Adds last wireguard handshake and received/sent bytes per peer
* feature: support new management service protocol
* chore: add more logging to track networkmap serial
* refactor: organize peer update code in engine
* chore: fix lint issues
* refactor: extract Signal client interface
* test: add signal client mock
* refactor: introduce Management Service client interface
* chore: place management and signal clients mocks to respective packages
* test: add Serial test to the engine
* fix: lint issues
* test: unit tests for a networkMapUpdate
* test: unit tests Sync update
