Item title should show year if the start or end date is outside of the current period

[florianhug]

Describe the bug
The bar in the chart displays the day and month of the start and end date associated with the item. If either of the two is outside of the selected period, the year should be shown additionally.

To Reproduce

1. Create an item with the start date 2019-12-23
2. Set the end date to 2020-04-28
3. In the year display set the year to 2020
4. See error: bar title is someitem (23. 12. - 28. 4.)

Expected behavior
The title should be someitem (23. 12. 2020 - 28. 4.)

Additional context
There are implications from the user's chosen date format.