[FIX] website_sale_coupon: display product image for rewards

Go to web shop as guest
Add 10 office chair black
Go to checkout
Add coupon code 10pc
Image for the reward prod will be displayed correctly
Proceed in checkout flow

Image is not displayed anymore

opw-2289771

closes odoo/odoo#54367

Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/website_sale_coupon/views/website_sale_templates.xml

@@ -6,6 +6,16 @@
         <script type="text/javascript" src="/website_sale_coupon/static/tests/tours/website_sale_coupon.js"></script>
     </xpath>
 </template>
+<template id="website_sale_coupon_cart_summary_show_img" inherit_id="website_sale.cart_summary">
+    <xpath expr="//td[hasclass('td-img')]/span" position="attributes">
+        <attribute name="t-if">not line.is_reward_line or not line.sudo().product_id.image_128</attribute>
+    </xpath>
+    <xpath expr="//td[hasclass('td-img')]/span" position="after">
+        <span t-if="line.is_reward_line and line.sudo().product_id.image_128">
+            <img t-att-src="image_data_uri(line.sudo().product_id.image_128)" class="img o_image_64_max rounded"/>
+        </span>
+    </xpath>
+</template>
 <template id="website_sale_coupon_cart_hide_qty" inherit_id="website_sale.cart_lines">
     <xpath expr="//td[hasclass('td-img')]/span" position="replace">
         <t t-if="line.is_reward_line and line.sudo().product_id.image_128">