Maint: port forwarding refactoring (#543)

- portforward package
- portforward run loop
- Less functional arguments and cycles

internal/portforward/status.go

@@ -0,0 +1,33 @@
+package portforward
+
+import (
+	"context"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/portforward/state"
+)
+
+func (l *Loop) GetStatus() (status models.LoopStatus) {
+	return l.statusManager.GetStatus()
+}
+
+type StartData = state.StartData
+
+type StartStopper interface {
+	Start(ctx context.Context, data StartData) (
+		outcome string, err error)
+	Stop(ctx context.Context) (outcome string, err error)
+}
+
+func (l *Loop) Start(ctx context.Context, data StartData) (
+	outcome string, err error) {
+	l.startMu.Lock()
+	defer l.startMu.Unlock()
+	l.state.SetStartData(data)
+	return l.statusManager.ApplyStatus(ctx, constants.Running)
+}
+
+func (l *Loop) Stop(ctx context.Context) (outcome string, err error) {
+	return l.statusManager.ApplyStatus(ctx, constants.Stopped)
+}