perf: query projected milestones for onboarding view (#6760)

* feat: support list milestones api

* show milestones in onboarding view

* add authenticated milestone

* add icon to login milestone

* update main

* lint

* fix import

* fix import

* lint

* reuse proto milestone type mapping

internal/api/grpc/admin/milestone.go

@@ -0,0 +1,24 @@
+package admin
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	object_pb "github.com/zitadel/zitadel/internal/api/grpc/object"
+	"github.com/zitadel/zitadel/pkg/grpc/admin"
+)
+
+func (s *Server) ListMilestones(ctx context.Context, req *admin.ListMilestonesRequest) (*admin.ListMilestonesResponse, error) {
+	queries, err := listMilestonesToModel(authz.GetInstance(ctx).InstanceID(), req)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := s.query.SearchMilestones(ctx, []string{authz.GetInstance(ctx).InstanceID()}, queries)
+	if err != nil {
+		return nil, err
+	}
+	return &admin.ListMilestonesResponse{
+		Result:  milestoneViewsToPb(resp.Milestones),
+		Details: object_pb.ToListDetails(resp.Count, resp.Sequence, resp.LastRun),
+	}, nil
+}