usePreferences behavior is unexpected when used outside of Configurable

[KilianB]

What you were expecting:

I would have expected the hook usePreferences to save a value inside the RaStore.preferences path.

If usePreferences is not to be used outside of a Configurable (which in my opinion it should be based on the name), at least a a warning should be printed to the console if the PreferenceKeyContext is not provided or empty.

What happened instead:

The key value forwarded to the setItem function in the store is empty, resulting in a value being set for RaStore. no matter what the actual key is.

Steps to reproduce:

• Use the following code snipped outside of a Configurable component

   //Does not work but should be identical to the hook below
   const [showExpertView, setShowExpertView] = usePreferences(
    "expertView",
    false,
  );
  
 //Works
  const [showExpertView, setShowExpertView] = useStore(
    "preferences.expertView",
    false,
  );

[fzaninotto]

you're right, if usePreferences is used outside of the right context, we should throw an error inviting to use useStore instead.

Would you like to open a PR about it?