Set height 100% (#4463)

Co-authored-by: Denis Voituron <[email protected]>

Author: MarvinKlein1508

examples/Demo/FluentUI.Demo.Client/Layout/DemoNav.razor

@@ -1,7 +1,7 @@
 @inject NavigationManager Navigation
 @inject FluentUI.Demo.DocViewer.Services.DocViewerService DocViewerService
 
-<FluentNav Style="padding-top:10px;"
+<FluentNav Style="padding-top:10px; height: 100%;"
 		   UseSingleExpanded="false"
 		   Density="@NavDensity.Medium">