Show information about _Planned update_ in the project list

[l00mi]

• [x] In the "More Details" pane of the project list show the date
• [x] In the list show the amount of days until planned update (show months if more than 30 days). Color red if less then 20 days. (Show in the middle of the project list.)

[l00mi]

Inform https://gitlab.ldbar.ch/bafu/umweltdatenkiosk-planning/-/issues/416 once done.