Feature/treeview
- component communication: switched to event bus instead of emitter due to modularization
- items sorted
- fixed missing image.id
- OSD detached from content and reattached to item
- modularized treeview and navbuttons. both now live in their own component
- browse by chapter
- toggle chapters in treeview by click
- ^^ update the corresponding prefix symbol
Edited by schneider210