title: Change partially_book_days to fully_booked_days if partial booked day
body: <p>I can not isolate the hook to make a partial_booked day change the day to fully_booked once a customer places an order for that day... I want to only allow one booking per day yet there must be the option to select any hour of the day for start_time (between 8AM and 9PM). </p>
  
  <p>I have tried several Availability settings in the product editor and even by using priorities for multiple selections of hour block or using a buffer, there is no option to create a datepicker output of <code>fully_booked</code> once the customer picks the hour they want to book. (We are delivering product and can only deliver one a day... but there has to be a time to choose when to deliver so we can not make the product Availability block all day "selectable.")</p>
  
  <p><strong>What I have tried:</strong></p>
  
  <pre><code>$booking_form_params = array('ajax_url' =&gt; WC()-&gt;ajax_url(), 
  'i18n_date_partially_booked' =&gt; __('This date is unavailable', 
                                  'woocommerce-bookings'), 
  @uses add_filter( 'booking_form_params' .... );
  </code></pre>
  
  <p>(this works on the front end perfectly well but the datepicker still allows clicking event if time left in the day) <strong>So of course I tried:</strong></p>
  
  <pre><code>$htm .= '.single.single-product td.partial_booked[data-event="click"] *{ 
  pointer-events: unset; cursor:not-allowed !important;
  background: #c96259!important;}';
  wp_register_style( 'codeoctober-entry-set', false );
  wp_enqueue_style(   'codeoctober-entry-set' );
  wp_add_inline_style( 'codeoctober-entry-set', $htm );
  }
  @using add_action( 'wp_footer', .... ); and add_action('wp_enqueue_scripts'....);
  </code></pre>
  
  <p><code>wp_enqueue_scripts</code> works great and makes the entire day field (td > a div) of calendar turn a nice bright red... But I still have that pesky click available.</p>
  
  <p><strong>So next I tried:</strong> 
  Some inline javascript in about a dozen different fashions and each time I tried to <code>.removeClass</code> or <code>.addClass()</code> or even <code>.replace(regex)</code> in hopes that the td anchor would honor my request to remove the <code>bookable</code> class. Results: nada! </p>
  
  <p>If I could remove the bookable class then I am good to go. We just do not want any one to select a day if another customer has booked any block of time (minimum blocks are four hours).</p>
  
  <p><strong>Was hoping it was as simple as this:</strong></p>
  
  <pre><code>add_filter( 'wc_bookings_date_picker_args', 'function-name');
  function-name
  {   $booked = 
          $wc_bookings_date_picker_args-&gt;booking_form-&gt;product-&gt;get_id() );
  
      return array(
          'partially_booked_days' =&gt; $booked['fully_booked_days'],
      );
  }
  </code></pre>