* overseer: remove mut in connector
* rename SelectRelayChainWFallback -> SelectRelayChain
* split Basics
* introduce the OverseerConnector, use it
* introduce is_relay_chain to RelayChainSelection
* chore: rename var
* avoid dummy import in subsystem
* actually remove Disconnecte/Connected enum
* extract DummySubsystem into mod dummy.
* Handle::Connected -> Handle::new
* chore: fmt
* fix test
* select relay chain takes no arg, simplification
* fmt
* Update node/service/src/lib.rs
Co-authored-by: Andronik Ordian <write@reusable.software>
* chore: improve malus tests
* avoid the deferred setting of `is_relay_chain` in `RelayChainSelection`
* positive assertion is not mandated, only the negative one, to avoid a stall
* chore: fmt
* assure the `RelayChainSelection` is not used before the overseer is up and running
Co-authored-by: Andronik Ordian <write@reusable.software>
Bernhard Schuster