Audio editor bugfixes - #283

Cannot convert null literal to non-nullable reference type.

Possible null reference argument for parameter 'packFile' in 'Window IEditorCreator.CreateWindow(PackFile packFile, EditorEnums? preferedEditor = null)'.

Non-nullable field '_activeConfig' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of type of parameter 'value' doesn't match overridden member (possibly because of nullability attributes).

Nullability of type of parameter 'existingValue' doesn't match overridden member (possibly because of nullability attributes).

Nullability in constraints for type parameter 'T' of method 'ScopeRepository.GetRequiredService<T>(IEditorInterface)' doesn't match the constraints for type parameter 'T' of interface method 'IScopeRepository.GetRequiredService<T>(IEditorInterface)'. Consider using an explicit interface implementation instead.