- using :host-context(.nightMode) allows for applying the nightmode
scroll bar inside the component
- apply max-width: 100% to all element within editable, not just images
- Rework V2 upgrade so that it no longer resets cards in learning,
or empties filtered decks.
- V1 users will receive a message at the top of the deck list
encouraging them to upgrade, and they can upgrade directly from that
screen.
- The setting in the preferences screen has been removed, so users
will need to use an older Anki version if they wish to switch back to
V1.
- Prevent V2 exports with scheduling from being importable into a V1
collection - the code was previously allowing this when it shouldn't
have been.
- New collections still default to v1 at the moment.
Also add helper to get map of decks and deck configs, as there were
a few places in the codebase where that was required.
* Custom elements are now namespaces with `anki-`
* The element names are inspired by summernote, which have the same
naming scheme of "editingArea > editable"
* also changed name of topbutton container back to topbutsOuter as it is clearer
* starting with Chromium 83, `row-gap` would be better suited for this
