chore(all): return concrete types, accept interfaces

- Remove exported interfaces unused locally
- Define interfaces to accept arguments
- Return concrete types, not interfaces

internal/loopstate/set.go

@@ -2,10 +2,6 @@ package loopstate
 
 import "github.com/qdm12/gluetun/internal/models"
 
-type Setter interface {
-	SetStatus(status models.LoopStatus)
-}
-
 // SetStatus sets the status thread safely.
 // It should only be called by the loop internal code since
 // it does not interact with the loop code directly.