fix: weekbased calculation pdf report

with this change the time calculations for pdf reports should be better
line with the reports send as "week_report"

Backend/models/workWeek_test.go

@@ -20,7 +20,7 @@ func TestNewWorkWeekNoPopulate(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	workWeek := models.NewWorkWeek(testUser, monday, false)
+	workWeek := models.NewWorkWeekSimple(testUser, monday, false)
 
 	if workWeek.User != testUser || workWeek.WeekStart != monday {
 		t.Error("No populate workweek does not have right values!")