Update Framework Databinding How-To

[adegeo]

Summary

• Rewrite .NET Framework WPF databinding article.
• Recode C# and XAML to demonstrate an Employee data object and view.
• Updated .NET's WPF databinding overview to show its data object.

Fixes #1860

@IEvangelist Just checkout the wording on the non-Framework file as the content is 99% the same between both versions of the file. They're they same but slightly tuned for Framework and non-Framework for links.

File in GitHub: https://github.com/dotnet/docs-desktop/pull/1868/files#diff-6c1179ceeab49612218bf13bd09449ef751ea565ca28cd51c2754bf85187fd2c

Preview: https://review.learn.microsoft.com/en-us/dotnet/desktop/wpf/data/how-to-create-a-simple-binding?branch=pr-en-us-1868&view=netdesktop-7.0

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Internal previews

📄 File	🔗 Preview link
dotnet-desktop-guide/framework/wpf/data/how-to-create-a-simple-binding.md	How to: Create a Simple Binding
dotnet-desktop-guide/net/wpf/data/binding-declarations-overview.md	Binding declarations overview (WPF .NET)
dotnet-desktop-guide/net/wpf/data/how-to-create-a-simple-binding.md	dotnet-desktop-guide/net/wpf/data/how-to-create-a-simple-binding

[IEvangelist]

LGTM, had a few suggestions.