Unit test with testcontainers

[hoangthanh28]

Hi Erik.
I plan to contribute to grate because I love it. It's a great tool, please consider my PR with the following changes:

• Refactoring the current unit test with testcontainers
• Migrate the current NUnit to xUnit (I believe xUnit will be better for us in the long run)
• Speedup the SqlServer Unit test, the duration is reduced from 21mins to 2mins
• Adjust the code format using dotnet format (I'm using Debian 12, vs code and C# DevKit). Please let me know what the best option is for us to follow in terms of code formatting. Feel free to prune/reformat the code if needed. Sorry for the inconsistent style with yours.

[erikbra]

Hi, @hoangthanh28. Thanks a lot for your PR! Great that you love great (pun intended), and even better that you would like to contribute! This is what open source should be, collaboration! :)

I originally used NUnit for grate, partly because it was used in RoundhousE, and partly because the "run this thing once before all tests" was easier in NUnit, at least I thought so at the time. So I used that for setting up the containers before running the tests. But I like xUnit better personally as well.

Your PR is quite big, so I'll have to take a little while looking into it, but initially I'm positive to the initiatives!

[hoangthanh28]

Thank you Erik for your consideration. Btw, I'm a 5-year RoundHousE user, as well as a big fan of database first, changing database is crucial, so we need to script it down and put into the version control system. :)

[erikbra]

Thanks again, @hoangthanh28 - I have looked through it, and it looks very clean and good quality code, I like it!
In general, I would prefer having only one type of change in each PR, it's easier to see what is changed (e.g. changing to TestContainers, or changing to xUnit), but I understand that they might walk a bit hand-in-hand, as the dependency injection might have changed.

I'm going to merge this as-is. I have a few suggestions for improvements, but I'll just make a separate PR myself into main for them.