When approving a leave, to make an informed decision, it might
be needed to check leaves already taken by the employee or leaves
of its collaborators. This commit adds a widget displaying some stats
in a leave form view. Stats displayed are:
- the number of days taken
by the employee this year, grouped by leave type
- Leaves taken by employees in the same department in the month
of the leave.
This widget is only displayed in the context of the action leading
to leaves to approve.
Xavier Dubuc