[macOS][NavigationView] When menu is contracted icons are clipped on the right

[StewartPolsky]

Current behavior

Expected behavior

How to reproduce it (as minimally and precisely as possible)

1. Launch app
2. Contract NavigationView
3. Notice that icons are clipped on the right side

Environment

Nuget Package:

Package Version(s):

Affected platform(s):

• iOS
• Android
• WebAssembly
• UWP
• MacOS

Anything else we need to know?

[dr1rrb]

This issue is actually caused by a settings of the system

Investigating how we could handle this properly ...

[dr1rrb]

So basically it means that when the display mode is "always" we should add the width of the scroll bar to the NavigationView.CompactPaneLenght. The issue is that this property is directly bound to the SplitView, so currenlty fixing this would mean either:

• Authoritatively add the SB width in set (so NV.CompactPaneLenght = 100; Assert.IsTrue(NV.CompactPaneLenght == 100); would fail)
• Break the compatibility with the UWP NavigationView's template by adding a special case.

Instead we will keep this as-is for now, and we will add support of the managed ScrollBar in the ScrollViewer for MacOS, which will give us greater control for the different display mode in that case.

[MatFillion]

@dr1rrb we don't have compact view in Uno.Gallery so it's ok to leave as is for now.