Fix Culture creation regression when using invalid names on Windows

[tarekgh]

#57310

This change is fixing a regression from .NET 5.0. The problem happens when trying to create a CultureInfo object using culture names that Windows don't allow.
This regression occurred during the code refactoring work done to optimize the globalization data size and WASM support.
Although this fix is addressing the regression, it fixes another issue I have discovered during the investigation. Here is what the change is doing:

• In the file CultureData.Windows.cs, the condition ShouldUseUserOverrideNlsData is wrong to use. The reason is this part of the code is not concerned about the user overrides. Even the user overrides flag is not initialized yet at this stage.
• In the same file, I added the call to Windows API GetLocaleInfoEx that help validate the culture name. That is what we have done in .NET 5.0 too.
• In the file IcuLocaleData.cs, there was a bug that caused not finding the proper culture name mapping to our data because the culture name containing characters like underscore character _.
• Fixing and adding tests.

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Issue Details

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Fixes #57310

This change is fixing a regression from .NET 5.0. The problem happens when trying to create a CultureInfo object using culture names that Windows don't allow.
This regression occurred during the code refactoring work done to optimize the globalization data size and WASM support.
Although this fix is addressing the regression, it fixes another issue I have discovered during the investigation. Here is what the change is doing:

• In the file CultureData.Windows.cs, the condition ShouldUseUserOverrideNlsData is wrong to use. The reason is this part of the code is not concerned about the user overrides. Even the user overrides flag is not initialized yet at this stage.
• In the same file, I added the call to Windows API GetLocaleInfoEx that help validate the culture name. That is what we have done in .NET 5.0 too.
• In the file IcuLocaleData.cs, there was a bug that caused not finding the proper culture name mapping to our data because the culture name containing characters like underscore _.
• Fixing and adding tests.

Author:	tarekgh
Assignees:	-
Labels:	area-System.Globalization
Milestone:	-

[tarekgh]

@ericstj @jeffhandley just FYI. this is a fix I am going to port to rc2 when it is ready. OfCourse, will loop you on the porting PR at that time.

[eerhardt]

LGTM

[tarekgh]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1151573976