Maint: move Openvpn package files

- Move internal/openvpn/config/*.go to internal/openvpn/
- Move internal/openvpn/setup.go to internal/vpn/openvpn.go

internal/openvpn/openvpn.go

@@ -0,0 +1,36 @@
+package openvpn
+
+import (
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/golibs/command"
+	"github.com/qdm12/golibs/logging"
+)
+
+var _ Interface = (*Configurator)(nil)
+
+type Interface interface {
+	VersionGetter
+	AuthWriter
+	Runner
+	Writer
+}
+
+type Configurator struct {
+	logger       logging.Logger
+	cmder        command.RunStarter
+	configPath   string
+	authFilePath string
+	puid, pgid   int
+}
+
+func New(logger logging.Logger,
+	cmder command.RunStarter, puid, pgid int) *Configurator {
+	return &Configurator{
+		logger:       logger,
+		cmder:        cmder,
+		configPath:   constants.OpenVPNConf,
+		authFilePath: constants.OpenVPNAuthConf,
+		puid:         puid,
+		pgid:         pgid,
+	}
+}