Add sample for `JumpList` API

[MartinZikmund]

What would you like to be added:

Uno Gallery sample on using JumpList API . See

• https://github.com/MartinZikmund/uno-unexpected-apis/blob/master/UnexpectedApisDemo/UnexpectedApisDemo.Shared/Views/JumpListPage.xaml
• https://github.com/MartinZikmund/uno-unexpected-apis/blob/master/UnexpectedApisDemo/UnexpectedApisDemo.Shared/Views/JumpListPage.xaml.cs
• https://github.com/unoplatform/uno/tree/master/src/Uno.UWP/UI/StartScreen

Why is this needed:

Developer samples

For which Platform:

All

[766974616c79]

I would like to do this

[MartinZikmund]

Hi @MoskalykA, assigned 👍 ! Let me know if you need anything

[p3rid0t]

Hi, I'd like to work on this issue :)