qml: refactors around navigation bar
Some refactors around navigation bar and its associated states
- Update keyboard navigation within the navigation bar
- Factorize how page properties are exposed (isSearchable, sortModel, etc...)
- Move search & sort context as sub models of MainCtx as state is shared across component. page model is no longer exposed to the navigation banner, this avoids weird constructions where models bind one the other to get the search/sort order.
- Remove obsolete features
- Remove some superfluous FocusScope
first commits are from !4273 (merged)