Added
* Ported channel related features to CocoImage
* vidshapes-msi is now an alias for vidshapes-multispectral
* Can now specify general channels for video toydata
Changed
* Split `kwcoco.demo.toydata` into `kwcoco.demo.toydata_image` and `kwcoco.demo.toydata_video`
* Moved code from `coco_dataset` to `_helpers`
Fixed
* Bug in `show_image` with MSI
* Fixed bug in ObjectList1D.peek