Allow to use .navigation-sidebar styleclass outside of stacksidebar

### Problem

Currently .navigation-sidebar is limited to stacksidebar. However the concept of a navigation sidebar is really common and very seldomly is stacksidebar enough. Much more often you have a single view where you fill the content depending on the selection. For example there are a few cases in mail (the main sidebar, the signature editor, etc.), the sidebar in files and also a few personal projects of mine, etc.
I think it would be great to have the styles of sidebars like that unified across all apps.

### Proposal

Allow to use navigation sidebar (or a new style class) on any listbox and listview/gridview.

### Prior Art (Optional)

Adwaita does that and it's used in most libadwaita apps which makes it a very unified feel which IMO is great.

Start by locating the navigation-sidebar style class and its stacksidebar styling, then inspect how listbox, listview, and gridview styles are defined. Confirm the intended behavior with the existing sidebar examples; done means the navigation-sidebar styling can be used on those views outside stacksidebar.

Written by the indexing model from the issue text.