Remove wp-show and wp-text directives

[DAreRodz]

This PR eliminates wp-show and wp-text directives, as they're not required for now. The wp-link directive, which is also not needed, has already been removed in #216.

[DAreRodz]

I skipped this one because I didn't see clearly how to refactor this test without using wp-show. @luisherranz, can you take a look at this?

[DAreRodz]

We can remove this test for now, although I would prefer to have this case covered.

[luisherranz]

We can do something like this:

<div data-wp-island>
  <div data-wp-island>
    <div data-testid="island inside another island">
      <div data-wp-init="actions.appendText">
        <span>
          This should not have two spans appended because that means we hydrated
          twice.
        </span>
      </div>
    </div>
  </div>
</div>

appendText: ({ ref }) => {
  const span = document.createTextNode("Span");
  span.innerText = "some text";
  ref.appendChild(span);
};

And check that there's only one span or something similar.

But I think ref is currently broken due to this bug and data-wp-init is not implemented yet, so we can wait until then.

[luisherranz]

LGTM, David!

[luisherranz]

We can do something like this:

<div data-wp-island>
  <div data-wp-island>
    <div data-testid="island inside another island">
      <div data-wp-init="actions.appendText">
        <span>
          This should not have two spans appended because that means we hydrated
          twice.
        </span>
      </div>
    </div>
  </div>
</div>

appendText: ({ ref }) => {
  const span = document.createTextNode("Span");
  span.innerText = "some text";
  ref.appendChild(span);
};

And check that there's only one span or something similar.

But I think ref is currently broken due to this bug and data-wp-init is not implemented yet, so we can wait until then.

[luisherranz]

There's a state.trueValue as well if you prefer.