Proxy: Add Hysteria 2 inbound & transport (supports listening port range, Salamander finalmask) (#5679)

https://github.com/XTLS/Xray-core/pull/5679#issuecomment-3888548778

Closes https://github.com/XTLS/Xray-core/issues/5605

proxy/hysteria/ctx/ctx.go

@@ -2,12 +2,15 @@ package ctx
 
 import (
 	"context"
+
+	"github.com/xtls/xray-core/proxy/hysteria/account"
 )
 
 type key int
 
 const (
 	requireDatagram key = iota
+	validator
 )
 
 func ContextWithRequireDatagram(ctx context.Context, udp bool) context.Context {
@@ -21,3 +24,12 @@ func RequireDatagramFromContext(ctx context.Context) bool {
 	_, ok := ctx.Value(requireDatagram).(struct{})
 	return ok
 }
+
+func ContextWithValidator(ctx context.Context, v *account.Validator) context.Context {
+	return context.WithValue(ctx, validator, v)
+}
+
+func ValidatorFromContext(ctx context.Context) *account.Validator {
+	v, _ := ctx.Value(validator).(*account.Validator)
+	return v
+}