Maint: interface composition for HTTP proxy loop

- Change SetStatus to ApplyStatus
- Add Runner interface
- Add SettingsGetterSetter alias to state.SettingsGetterSetter

internal/httpproxy/settings.go

@@ -4,8 +4,11 @@ import (
 	"context"
 
 	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/httpproxy/state"
 )
 
+type SettingsGetterSetter = state.SettingsGetterSetter
+
 func (l *looper) GetSettings() (settings configuration.HTTPProxy) {
 	return l.state.GetSettings()
 }