Allow splitting GodotDisabledSourceGenerators by comma (Updates ExtensionMethods.cs)

[InfiniteCactusDev]

Allows separating GodotDisabledSourceGenerators by comma

There's a bug in the Roslyn analyzers that describes the ; character being treated as a comment in the resulting editorconfig file and thus stripping all values after it: dotnet/roslyn#43970

I noticed this when trying to disable multiple source generators in my csproj file like so:

<GodotDisabledSourceGenerators>ScriptSignals;ScriptProperties</GodotDisabledSourceGenerators>

This results in the following line in *.GeneratedMSBuildEditorConfig.editorconfig:

    build_property.GodotDisabledSourceGenerators = ScriptSignals;ScriptProperties

Which results in only ScriptSignals to be disabled. ScriptProperties is ignored and doesn;t reach the checking-code.

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This change allows to also split the setting with a comma.

[paulloz]

Hello, and thank you for the contribution! ✨

The issue is indeed easily reproducible (just added unit tests for it). It looks like there was some recent movement on dotnet/roslyn#51625. If the issue is being fixed upstream, I would rather not introduce an ad-hoc behaviour on our end as a workaround. But I agree that it is currently problematic. Would love to get the insights of other contributors.

[InfiniteCactusDev]

The reason behind the comma is that it's the next best logic separator to use and it's backwards compatible (there's no generator with a comma in the name).

[Panthr75]

This PR fixes #91999