Fix VB type mismatch in DataGrid SQL EF walkthrough and migrate snippets (#2151)

* Initial plan

* Migrate DataGrid SQL EF snippets to new location and fix VB type mismatch

Co-authored-by: adegeo <[email protected]>

* Delete legacy DataGrid SQL EF snippet files

Co-authored-by: adegeo <[email protected]>

* Fix LINQ query formatting in C# MainWindow.xaml.cs

Co-authored-by: adegeo <[email protected]>

* Fix projects (#2159)

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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: adegeo <[email protected]>

Author: Copilot