Wagtail-photo-gallery

Fixed `CollectionChooserBlock` by adding `get_form_state()` (Issue 2):

py
class CollectionChooserBlock(blocks.ChooserBlock):

def get_form_state(self, value):
return self.widget.get_value_data(value)

Previously, leaving `Album.collection` empty resp. setting it to null was allowed.
Since the collection setting was moved to the _Settings_ tab, it was to easy to forget to set the `Collection`.

Now `Album.collection` defaults to _Root_, which is also more convenient if only a single gallery for all photos is used.

Changes

- [x] Deleting the collection now deletes every associated `Album` (cascade)
- [x] _Root_ is set as default for `Album.collection`, removed null and blank
- [x] _Root_ is set as default for `CollectionChooserBlock` when a `GalleryBlock` is added

Improvements

- [x] Fixed missing translation in templates

This update bring plenty UI improvements and translations.
Wagtail 4 and 5 are now supported.

Changelog

- [x] Updated imports for Wagtail 4 and 5. Fixes 7
- [x] Improved admin image visualization
- [x] Fixed layout issues (prior to Wagtail 4 panels used to render `<ul>`, but now use `<div>` instead). Fixes 6
- [x] Added [AlbumInlinePanel and AlbumMultiFieldPanel](https://github.com/donhauser/wagtail-photo-gallery/commit/ed6dbfac1c82e67515a38a593a3a4c500af4a756) to customize admin HTML generation
- [x] Improved the interaction with `AlbumInlinePanel` by adding buttons: _Add Image_, _Select All_, _Unselect_, _Delete Selected_
- [x] Add button now sets the thumbnail as well
- [x] Added proper Translation handling (Implemented 1). Pull requests for other languages are very welcome!
- [x] Added German Translation

*Bugfixes:*
- fixed css conflict with wagtail `.ui-sortable`
- fixed template crash, caused by instances of `Album` without any images