C#: Compare symbol names without null flow state

[raulsntos]

• Symbol.ToString() is equivalent to Symbol.ToDisplayString() which includes null flow state. This means the string would include ? for reference types when the may be null and the strings would not be equal.
• Fixes Exporting nullable Node in C# does not show the node selector inspector #79071.

[RedworkDE]

I don't think attributes can be nullable like that, but if we do those changes as well there is one left here: https://github.com/godotengine/godot/blob/f4d40c665df1b306b9168f97f19464ca2435f157/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptPropertiesGenerator.cs#L365

Semi-related: Is there something that guarantees that the source generator run using an invariant culture? If no there are (at least) two int.ToString() that can possibly break when running on some cultures.

[raulsntos]

I don't think attributes can be nullable like that

I don't think so either, but I thought we might as well.

Is there something that guarantees that the source generator run using an invariant culture?

I don't think so, it probably runs using the current culture. We probably have other cases of this in StringExtensions, so I'd prefer to do this as a separate PR that focuses on fixing all the culture warnings at once.

[akien-mga]

Thanks!

[YuriSizov]

Cherry-picked for 4.1.1.