Vacation overview

[viklund]

Please describe the feature

As a manager/nbis staff
I want an overview of when others have vacation
so that I know which of my collegeues are here when.

Detailed description

This probably needs to be refined more but these are considerations to have in mind:

• It's probably good to see things in a "calendar" like view, similar to a gantt chart
• People will want to filter out what collegues are visible, this could for example be based on which group someone is assigned in redmine.
• It should be possible to move start and end date for the view.
  • 3 months is a good "maximum" view.
• Handle partial absence in some way (ignore it is fine)

Additional context