Show total count of violations as number, but only mark in orange if there are any violations that are not manually resolved already

Allow AKSlot creation via scheduler

Closes #120

See merge request !145

This implements #120

Use target parent for virtual room buttons on room detail page, too

See merge request !144

Use target parent for remaining virtual room buttons on AK detail page, too

See merge request !143

Use target parent for going to virtual room buttons

See merge request !142

This ensures correct loading if AKPlan is called from within a frame, e.g., in Venueless

Fix room adding form

See merge request !140

Make sure calendar is only loaded when event was already set

Introduce view for room import from CSV

Closes #156

See merge request !139

This implements #156

Improve scheduling

Closes #93 and #159

See merge request !137

Load custom css in admin interface, too
Fix lading of locales in scheduler
Improve icon in scheduler
Reduce SQL query amount in scheduler

Create new view (including template and form)
Link on status page
Add translations

Move general ajax setup call to external js file
Move common functionality for CV loading to external js file
Visualize existing violations in scheduler
Add reloading function to scheduler

Adapt loading templates
Move plan loader template to AKModel
Add new template to load all css and scripts for availabilities with one call
Use that loader in views with availabilities editors

Additionally, move moments library to common

This used the common fullcalendar v5 instance instead of a special v3 version only for this editor
Improve visualization of availability deletion
Improve (event specific) timezone handling and remove dependency to moment-timezones

Create model
Create migration
Create admin interface

This mostly implements #159
Introduce a new field that denotes the timestamp when the plan was published
Introduce admin actions to publish and unpublish the plan and set that timestamp accordingly
Prevent other means to change visibility of the plan
Use that timestamp to only highlight recent changes when they occurred after the plan was already published

Load fonts from our server and not from Google Fonts

See merge request !138

Add new functionality to backend

Closes #153, #154, and #152

See merge request !133

Use action with intermediate page instead of direct action for publishing and unpublishing of plans
This allows to create a link on the events detail page and on the status page to change the plans visibility
Add link to detail view
Visualize plan visibility on status page and allow to toggle it from there
This implements the final function of #159

Move loop-based action code to mixin that will only be used when more complex actions should be performed
Use queryset update function on existing actions to perform the necessary updating in only one db call instead of one query per entity
Additionally, visualize manually_resolved status in admin interface of CV

Looks like this was broken since the switch to individual boxes per category.
Fixed it and made it more robust (show error message when trying to export AKs from more than one event at the same time).

Leverage the decorators introduced in django 3.2 for methods that do not use them already