added message for button name 'Schließen'
app formular: note if period spans 2 years

* if the given period spans 2 years show a message like "x days in year1
  and y days in year2)
* else show only a message like "x days"

refs #10961
overview: notice it if holiday spans 2 years

refs #10961
app-detail: notice for holiday that spans 2 years

refs #10961