fix ExpressionChangedAfterItHasBeenCheckedError in Weekview

[wp99cp]

If meals are moved too quickly one after the other, the database updater fires during the drag and drop process. This leads to an ExpressionChangedAfterItHasBeenCheckedError. At the moment the resulting errors are caught and the page is reloaded afterwards. A message is displayed to the user.

However, this error should not occur in the first place. To solve the problem, the correct CDK drag-drop lists must be used, which is not the case in the current implementation.