[Fluent] CommandBar Samples

[kazo0]

What would you like to be added:

Samples for the Fluent CommandBar

Uno guidance:
https://platform.uno/docs/articles/controls/CommandBar.html

Fluent guidance
https://docs.microsoft.com/en-us/uwp/api/windows.ui.xaml.controls.commandbar?view=winrt-19041

<CommandBar Background="Transparent" IsOpen="False" DefaultLabelPosition="Right">
    <AppBarButton Icon="Add" Label="Add"/>
    <AppBarButton Icon="Edit" Label="Edit"/>
    <AppBarButton Icon="Share" Label="Share"/>
    <CommandBar.SecondaryCommands>
        <AppBarButton Icon="Setting" Label="Settings">
            <AppBarButton.KeyboardAccelerators>
                    <KeyboardAccelerator Modifiers="Control" Key="I" />
            </AppBarButton.KeyboardAccelerators>
        </AppBarButton>
    </CommandBar.SecondaryCommands>
</CommandBar>

<CommandBar>
	<AppBarToggleButton Icon="Shuffle"
						Label="Shuffle" />
	<AppBarToggleButton Icon="RepeatAll"
						Label="Repeat" />
	<AppBarSeparator />
	<AppBarButton Icon="Back"
					Label="Back" />
	<AppBarButton Icon="Stop"
					Label="Stop" />
	<AppBarButton Icon="Play"
					Label="Play" />
	<AppBarButton Icon="Forward"
					Label="Forward" />

	<CommandBar.SecondaryCommands>
		<AppBarButton Icon="Like"
						Label="Like" />
		<AppBarButton Icon="Dislike"
						Label="Dislike" />
	</CommandBar.SecondaryCommands>
</CommandBar>

Why is this needed:

For which Platform:

• iOS
• Android
• WebAssembly
• WebAssembly renders for Xamarin.Forms
• Windows
• Build tasks

Anything else we need to know?