* Import things from `aqt.qt` not `PyQt5`/`PyQt6`
* When testing with Qt6, disable Anki's Qt5 compatibility mode
* Depend on `pytest-anki` that is also Qt version agnostic
Before, pressing the Browse button would only show browser
with the cards or notes corresponding to the currently edited note.
Now, it shows all cards or notes from the dialog history,
in reverse order (last seen on top),
with the currently edited note or its cards selected.
* make previewer use a more generic Adapter to flip through cards;
* return Previewer from `show_preview()` for testing,
* as well as Edit dialog from `open_dialog_and_show_note_with_id`;
* disable/enable `Edit` editor buttons more reliably;
* a few minor changes
Like Edit Current, but:
* has a Preview button to preview all cards for this note
* has a Browse button to open the browser with these
* has Previous/Back buttons to navigate the history of the dialog
* has no Close button bar
