title: Get WooCommerce product terms for all products shown in a category
body: <p>I've made a category in WooCommerce. In this category I've an amount of X products. All of my products has some terms. </p>
  
  <p>Now I want to display all product related terms in my category from the available products there. </p>
  
  <p>For example I've product A, B &amp; C. </p>
  
  <p>A has term: H
  B has term: K
  C has term: Z</p>
  
  <p>Product A &amp; C are in category 1. So I want just the terms H &amp; Z shown in this category. </p>
  
  <p>I've tried this here but this returns all available product terms, also from the products outside of the category:</p>
  
  <pre><code>$terms = get_terms('product_tag');
  </code></pre>