The current notes text view has had a 2px offset for
an unknown amount of time, due to us magic-numbering
margins and/or padding. This approach works a little
bit differently, in that it uses the `.editable-area`
style class and sets the overlay's CSS name to "box"
to use a predictable size of margins from AdwEntryRow.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/738>