qml/TableView: Improve and simplify model declarations

This MR improves models declarations for TableView(s) by switching to sub-model based models that integrate static properties in a separate dictionary. It also simplifies width handling to column sizes to enforce the grid policy when declaring a table model.

Building upon these changes it adds a "tiny model" to the comprehensive MusicTrackList view in the Music tab.

depends !2962 (merged)