XAML extensions for events to easy use markup extension syntax of animations

[HavenDV]

Makes it easier to use animations in MAUI
Allows to use animations in styles without any problems
Was

<Entry Placeholder="Animate on Focused and Unfocused">
    <Entry.Behaviors>
        <toolkit:AnimationBehavior EventName="Focused">
            <toolkit:AnimationBehavior.AnimationType>
                <behaviorPages:SampleScaleToAnimation 
                    Easing="{x:Static Easing.Linear}"
                    Length="100"
                    Scale="1.05"/>
            </toolkit:AnimationBehavior.AnimationType>
        </toolkit:AnimationBehavior>

        <toolkit:AnimationBehavior EventName="Unfocused">
            <toolkit:AnimationBehavior.AnimationType>
                <behaviorPages:SampleScaleToAnimation 
                    Easing="{x:Static Easing.Linear}"
                    Length="100"
                    Scale="1"/>
            </toolkit:AnimationBehavior.AnimationType>
        </toolkit:AnimationBehavior>
    </Entry.Behaviors>
</Entry>

Will become

<Entry Placeholder="Animate on Focused and Unfocused"
            toolkit:VisualElementAnimations.Focused="{toolkit:FadeAnimation Opacity=0.5, Length=500}"
            toolkit:VisualElementAnimations.Unfocused="{toolkit:FadeAnimation Opacity=0.5, Length=500}" />

We can use a separate namespace to not create noise in the main

[CliffAgius]

Closed as per the Community Stand-up discussion here: https://youtu.be/N9wMcBP4jtg?t=2889