chore!(amneziawg): refactor to be separate from wireguard

- amneziawg is now a VPN protocol and no longer a Wireguard implementation
- Use it with VPN_TYPE=amneziawg
- document AMNEZIAWG_* options in Dockerfile
- document amneziawg support in readme
- separate amneziawg settings and code from wireguard
- re-use code from wireguard whenever possible

internal/wireguard/log.go

@@ -1,5 +1,9 @@
 package wireguard
 
+import (
+	"golang.zx2c4.com/wireguard/device"
+)
+
 //go:generate mockgen -destination=log_mock_test.go -package wireguard . Logger
 
 type Logger interface {
@@ -7,5 +11,16 @@ type Logger interface {
 	Debugf(format string, args ...interface{})
 	Info(s string)
 	Error(s string)
-	Errorf(format string, args ...interface{})
+	Erroer
+}
+
+type Erroer interface {
+	Errorf(format string, args ...any)
+}
+
+func makeDeviceLogger(logger Logger) (deviceLogger *device.Logger) {
+	return &device.Logger{
+		Verbosef: logger.Debugf,
+		Errorf:   logger.Errorf,
+	}
 }