fix: rename OTP to TOTP in v2 alpha user api

This change renames the v2 user OTP registration endpoints and objects
to TOTP.
Also the v2 related code paths have been renamed to TOTP.

This change was discussed during the sprint review.

internal/api/grpc/user/v2/totp_test.go

@@ -0,0 +1,71 @@
+package user
+
+import (
+	"io"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/zitadel/zitadel/internal/domain"
+	object "github.com/zitadel/zitadel/pkg/grpc/object/v2alpha"
+	user "github.com/zitadel/zitadel/pkg/grpc/user/v2alpha"
+)
+
+func Test_totpDetailsToPb(t *testing.T) {
+	type args struct {
+		otp *domain.TOTP
+		err error
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    *user.RegisterTOTPResponse
+		wantErr error
+	}{
+		{
+			name: "error",
+			args: args{
+				err: io.ErrClosedPipe,
+			},
+			wantErr: io.ErrClosedPipe,
+		},
+		{
+			name: "success",
+			args: args{
+				otp: &domain.TOTP{
+					ObjectDetails: &domain.ObjectDetails{
+						Sequence:      123,
+						EventDate:     time.Unix(456, 789),
+						ResourceOwner: "me",
+					},
+					Secret: "secret",
+					URI:    "URI",
+				},
+			},
+			want: &user.RegisterTOTPResponse{
+				Details: &object.Details{
+					Sequence: 123,
+					ChangeDate: &timestamppb.Timestamp{
+						Seconds: 456,
+						Nanos:   789,
+					},
+					ResourceOwner: "me",
+				},
+				Secret: "secret",
+				Uri:    "URI",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := totpDetailsToPb(tt.args.otp, tt.args.err)
+			require.ErrorIs(t, err, tt.wantErr)
+			if !proto.Equal(tt.want, got) {
+				t.Errorf("RegisterTOTPResponse =\n%v\nwant\n%v", got, tt.want)
+			}
+		})
+	}
+}