IfcXml reading fails under Turkish culture (culture-sensitive ToUpper() in type lookup)

[oguzozshn]

Summary

The IfcXml readers resolve Express type names by upper-casing the XML element name with the
culture-sensitive string.ToUpper(), while the metadata dictionary is keyed on invariant upper
case. Under the Turkish (and Azeri) casing rules i maps to İ (U+0130), so the lookup never
matches:

tr-TR      "IfcOrganization".ToUpper()          => "IFCORGANİZATİON"
invariant  "IfcOrganization".ToUpperInvariant() => "IFCORGANIZATION"

Every IFC type name contains an i, so on a machine whose current culture is Turkish, reading
IfcXml fails completely.

Reproduction

[Theory]
[InlineData("en-US")]
[InlineData("tr-TR")]
public void Can_read_ifcxml_regardless_of_current_culture(string culture)
{
    var previous = CultureInfo.CurrentCulture;
    try
    {
        CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo(culture);

        using var model = new MemoryModel(new EntityFactoryIfc4());
        model.LoadXml(@"TestFiles\Dimensions.ifcxml");

        Assert.True(model.Instances.Count > 0);
    }
    finally
    {
        CultureInfo.CurrentCulture = previous;
    }
}

en-US passes. tr-TR fails with:

Xbim.Common.Exceptions.XbimParserException : IfcProjectLibraryis not an IPersistEntity type

Running the whole Xbim.Essentials.Tests suite on a tr-TR machine gives 30 failures on current
master (e3c8777), for both net48 and net10.0. A typical message is:

Error reading XML, Line=14, Position=6, Tag='IfcOrganization'
 ---> System.Exception: Illegal XML element tag

CI does not catch this because it runs under an English culture.

Affected call sites

Reading (the cause of the failures above):

• Xbim.IO.MemoryModel/Xml/XbimXmlReader4.cs - GetExpresType (2 calls)
• Xbim.IO.MemoryModel/Xml/XbimXmlReader3.cs - IsIfcProperty, IsIfcType (2 calls), IsIfcEntity

Writing (same class of problem, surfaced by the round-trip and serialization tests):

• Xbim.IO.MemoryModel/Xml/XbimXmlWriter4.cs - enum values
• Xbim.IO.MemoryModel/Xml/IfcXmlWriter3.cs - enum values
• Xbim.Common/Step21/Part21Writer.cs - select type names and enum values
• Xbim.Common/Step21/StepFileHeader.cs - schema name
• Xbim.IO.Esent/IPersistEntityExtensions.cs - select type names

Suggested fix

Use ToUpperInvariant() / ToLowerInvariant() on these paths. With that change the suites are
green on a tr-TR machine: 497/497 in Xbim.Essentials.Tests and 95/95 in
Xbim.Essentials.NetCore.Tests.

I have the fix and the culture-parameterised regression test working locally. Happy to open a PR
against develop if you would like it.

Environment

• XbimEssentials master @ e3c8777
• .NET SDK 10.0.302, targets net10.0 and net48
• Windows 11, CurrentCulture = tr-TR