[🐛 in esl-toggleable]: incorrect activator passed if out of the box close trigger has complex structure

[ala-n]

To Reproduce
Steps to reproduce the behavior:

1. Use the esl-togglable (or ESLToggleable-based) component with the following structure

  <esl-toggleable close-on=".btn">
      <button type="button" class="btn">
         <div>Close</div>
      </button>
  </esl-togglable>

2. Handle hide event:

 $togglable.addEventListener('esl:hide', (e) => {
    console.log(e.details.activator);
 });

3. Click on "Close" button
4. Observe passed activator

Current behavior
The current activator is equal e.target (which is nested div in that case)

Expected behavior
The activator should be equal to the marked actionable element .btn in that case