The keywording sheet's rows and its open/assign/unassign callbacks, the
star and flag callbacks a cell click or a judgement key fires, the burst
toggle and representative-chosen callbacks, the trash-selection shortcut,
and the rating/unjudged/flag filter chips with their rating-counts model
move from AppWindow onto the `Library` global started in the previous
commit. Rust reaches them through window.global::<Library>() rather than
window.set_/get_/on_ on the root.
dtourolle
00e2fe6aaf