refactor: Nullable and Modernization for Core Presentation projects

[Kryptos-FR]

PR Details

Similar to #2639 and #2643.

Description

Modernize the code, use nullable annotations, try to fix null reference warnings when possible.

Affected projects:

• Stride.Core.Presentation
• Stride.Core.Quantum
• Stride.Core.Quantum.Tests
• Stride.Core.Presentation.Quantum
• Stride.Core.Presentation.Quantum.Tests

I purposely left out Stride.Core.Presentation.Wpf as well as Stride.Core.Presentation.Tests as I consider those legacy since we are moving towards using Avalonia in the near future.

Dispose pattern

I also fix the Dispose pattern in some places. It was previously implemented as follow:

class BaseClass : IDisposable
{
    public virtual void Dispose()
    {
        // dispose stuff
    }
}

class DerivedClass : BaseClass
{
    public override void Dispose()
    {
        // dispose other stuff
        base.Dispose();
    }
}

The main issue is that if any derived class does have a finalizer (because it has to release unmanaged resources), it will be broken : finalizer are not supposed to call managed code (included from ancestor classes), as it can lead to unpredictable/undefined behavior. More details https://learn.microsoft.com/en-us/dotnet/standard/garbage-collection/implementing-dispose and https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/dispose-pattern.

The correct implementation (according to the guidelines linked above) is:

class BaseClass : IDisposable
{
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (disposing)
        {
            // dispose stuff
        }
    }
}

class DerivedClass : BaseClass
{
    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            // dispose other stuff
        }
        base.Dispose(disposing);
    }
}

Related issues

#2155
#2156

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.

[Eideren]

Thanks !