Maint: port forwarding refactoring (#543)

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

internal/portforward/helpers.go

@@ -0,0 +1,22 @@
+package portforward
+
+import (
+	"context"
+	"time"
+)
+
+func (l *Loop) logAndWait(ctx context.Context, err error) {
+	if err != nil {
+		l.logger.Error(err.Error())
+	}
+	l.logger.Info("retrying in " + l.backoffTime.String())
+	timer := time.NewTimer(l.backoffTime)
+	l.backoffTime *= 2
+	select {
+	case <-timer.C:
+	case <-ctx.Done():
+		if !timer.Stop() {
+			<-timer.C
+		}
+	}
+}