feat: device authorization RFC 8628 (#5646)

* device auth: implement the write events

* add grant type device code

* fix(init): check if default value implements stringer

---------

Co-authored-by: adlerhurst <silvan.reusser@gmail.com>

internal/repository/deviceauth/constraints.go

@@ -0,0 +1,46 @@
+package deviceauth
+
+import (
+	"strings"
+
+	"github.com/zitadel/zitadel/internal/eventstore"
+)
+
+const (
+	UniqueUserCode      = "user_code"
+	UniqueDeviceCode    = "device_code"
+	DuplicateUserCode   = "Errors.DeviceUserCode.AlreadyExists"
+	DuplicateDeviceCode = "Errors.DeviceCode.AlreadyExists"
+)
+
+func deviceCodeUniqueField(clientID, deviceCode string) string {
+	return strings.Join([]string{clientID, deviceCode}, ":")
+}
+
+func NewAddUniqueConstraints(clientID, deviceCode, userCode string) []*eventstore.EventUniqueConstraint {
+	return []*eventstore.EventUniqueConstraint{
+		eventstore.NewAddEventUniqueConstraint(
+			UniqueDeviceCode,
+			deviceCodeUniqueField(clientID, deviceCode),
+			DuplicateDeviceCode,
+		),
+		eventstore.NewAddEventUniqueConstraint(
+			UniqueUserCode,
+			userCode,
+			DuplicateUserCode,
+		),
+	}
+}
+
+func NewRemoveUniqueConstraints(clientID, deviceCode, userCode string) []*eventstore.EventUniqueConstraint {
+	return []*eventstore.EventUniqueConstraint{
+		eventstore.NewRemoveEventUniqueConstraint(
+			UniqueDeviceCode,
+			deviceCodeUniqueField(clientID, deviceCode),
+		),
+		eventstore.NewRemoveEventUniqueConstraint(
+			UniqueUserCode,
+			userCode,
+		),
+	}
+}