Allow unloading scenes with any valid reference

[joaoborks]

At the current version (3.0.x), to unload a scene you need to either use a direct LoadSceneInfoScene with the target scene reference, or the same ILoadSceneInfo that loaded it in the first place.

The package should allow unloading a scene from any ILoadSceneInfo that can point to a loaded scene. This is not possible to do with addressable scenes.

So, the scene load/unload table would be:

Load \ Unload	LoadSceneInfoScene	LoadSceneInfoName	LoadSceneInfoIndex	LoadSceneInfoAddress	LoadSceneInfoAssetReference
LoadSceneInfoName	✅	✅	✅	❌	❌
LoadSceneInfoIndex	✅	✅	✅	❌	❌
LoadSceneInfoAddress	✅	❌	❌	✅	❌
LoadSceneInfoAssetReference	✅	❌	❌	❌	✅