Convenience extension methods

## Describe the task

CreateEffect and the like expect a certain function signature, but we often end up doing discard params, some ext methods that make that a bit cleaner by wrapping them would be nice.

## Additional context

```
fluxityInitializer.CreateEffect(OnInitialiseGame);

//and

private void OnInitialiseGame(InitialiseGameCommand _1, IDispatcher _2)
{
_sfxMusicSystem.Begin();
}
```

Start by finding the CreateEffect API and related initializer methods, then compare their expected delegate signatures with the example that has unused InitialiseGameCommand and IDispatcher parameters. The goal is to add convenience extension methods that let callers avoid discard parameters while still wrapping into the existing signatures.

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