title: Add a custom text to Woocommerce product availability and display it for cart items
body: <p>I'm trying to find a way to place custom text before availability info (out of stock, in stock etc.) on woocommerce single product page. </p>
  
  <p>I am using something like that:</p>
  
  <pre><code>add_filter( 'woocommerce_get_availability', 'change_product_availability_display' ); 
  add_filter( 'unknown filter', 'change_product_availability_display' );
  function change_product_availability_display( $availability ) {
      // Additional text 
      $text = __('Availability:'); 
      // returning the text before the availability 
      return $text . ' ' . $availability; 
  }
  </code></pre>
  
  <p>Its's based on: <a href="https://stackoverflow.com/questions/47016425/add-a-custom-text-before-the-price-display-in-woocommerce">Add a custom text before the price display in WooCommerce</a>. </p>
  
  <p>In case of price filter named in my code "unknown filter" was <code>woocommerce_cart_item_price</code>. I've looked for this kind of filter for availability/stock item, but can't find it. </p>
  
  <p>Maybe someone could review this code and help me to find this "<code>unknown_filter</code>" or have other idea how I can put custom text before availability info?</p>