Refactor struct & Add override dialer options

outbound/dialer/dialer.go

@@ -0,0 +1,21 @@
+package dialer
+
+import (
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+	N "github.com/sagernet/sing/common/network"
+)
+
+func New(router adapter.Router, options option.DialerOptions) N.Dialer {
+	var dialer N.Dialer
+	if options.Detour == "" {
+		dialer = newDefault(options)
+	} else {
+		dialer = newDetour(router, options)
+	}
+	if options.OverrideOptions != nil {
+		dialer = newOverride(dialer, common.PtrValueOrDefault(options.OverrideOptions))
+	}
+	return dialer
+}