AKModel/AKScheduling: Introduce and use default slots for events

• Allow to create default slots for event (model and view, prefered calendar view)
• Visualize default slots in scheduling view
• Adapt existing background visualizing in scheduling view (room availability, e.g., using light red areas for times where room is not available instead of green area for available times, allowing to add e.g., light blue areas for default slots) and adapt checking

added feature label

changed milestone to %KIF 50,7

assigned to @bhaettasch

• Create warning when AK was placed outside default slot
• Create warning when AK was placed in a slot primarily for other than its categories

marked the checklist item Adapt existing background visualizing in scheduling view (room availability, e.g., using light red areas for times where room is not available instead of green area for available times, allowing to add e.g., light blue areas for default slots) and adapt checking as completed

marked the checklist item Allow to create default slots for event (model and view, prefered calendar view) as completed

marked the checklist item Visualize default slots in scheduling view as completed

Main functionality was introduced with !137 (merged), remaining functionality was moved to #163

closed