fix(user fields): missing creationDate in details (#9250)

# Which Problems Are Solved

The `creationDate` property on user search V2 endpoint was missing

# How the Problems Are Solved

Added property in v2 `object.proto` and in the function creating the
details on each call

# Additional Changes
- none
# Additional Context
closes #8552

---------

Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>

internal/api/grpc/user/v2beta/u2f_test.go

@@ -43,6 +43,7 @@ func Test_u2fRegistrationDetailsToPb(t *testing.T) {
 					ObjectDetails: &domain.ObjectDetails{
 						Sequence:      22,
 						EventDate:     time.Unix(3000, 22),
+						CreationDate:  time.Unix(3000, 22),
 						ResourceOwner: "me",
 					},
 					ID:                                 "123",
@@ -59,6 +60,7 @@ func Test_u2fRegistrationDetailsToPb(t *testing.T) {
 					ObjectDetails: &domain.ObjectDetails{
 						Sequence:      22,
 						EventDate:     time.Unix(3000, 22),
+						CreationDate:  time.Unix(3000, 22),
 						ResourceOwner: "me",
 					},
 					ID:                                 "123",
@@ -69,6 +71,10 @@ func Test_u2fRegistrationDetailsToPb(t *testing.T) {
 			want: &user.RegisterU2FResponse{
 				Details: &object.Details{
 					Sequence: 22,
+					CreationDate: &timestamppb.Timestamp{
+						Seconds: 3000,
+						Nanos:   22,
+					},
 					ChangeDate: &timestamppb.Timestamp{
 						Seconds: 3000,
 						Nanos:   22,