fix(projections): user idp link projection (#2583)

* fix(projections): add app

* fix(migration): add index for project_id

* test: app projection

* fix(projections): add idp_user_link

* test: idp user link

* fix: migration versions

* refactor: rename externalIDP to UserIDPLink

* fix: interface methods

internal/domain/user_idp_link.go

@@ -0,0 +1,29 @@
+package domain
+
+import es_models "github.com/caos/zitadel/internal/eventstore/v1/models"
+
+type UserIDPLink struct {
+	es_models.ObjectRoot
+
+	IDPConfigID    string
+	ExternalUserID string
+	DisplayName    string
+}
+
+func (idp *UserIDPLink) IsValid() bool {
+	return idp.IDPConfigID != "" && idp.ExternalUserID != ""
+}
+
+type UserIDPLinkState int32
+
+const (
+	UserIDPLinkStateUnspecified UserIDPLinkState = iota
+	UserIDPLinkStateActive
+	UserIDPLinkStateRemoved
+
+	userIDPLinkStateCount
+)
+
+func (s UserIDPLinkState) Valid() bool {
+	return s >= 0 && s < userIDPLinkStateCount
+}