feat(views)!: move task position handling to its own crud entity

BREAKING CHANGE: the position of tasks now can't be updated anymore via the task update endpoint. Instead, there is a new endpoint which takes the project view into account as well.

pkg/models/task_collection.go

@@ -67,7 +67,6 @@ func validateTaskField(fieldName string) error {
 		taskPropertyCreated,
 		taskPropertyUpdated,
 		taskPropertyPosition,
-		taskPropertyKanbanPosition,
 		taskPropertyBucketID,
 		taskPropertyIndex:
 		return nil