[IMP] website_quote: use affix to block the sidebar when scrolling

Sometimes, the sidebar on quotation previews can overflow the footer
if the window height is too small. To prevent that, the position of
the sidebar is blocked before overflowing, thanks to affix.

addons/website_quote/static/src/js/website_quotation.js

@@ -175,6 +175,12 @@ if(!$('.o_website_quote').length) {
     nav_menu.setElement($('[data-id="quote_sidebar"]'));
     nav_menu.start($('body[data-target=".navspy"]'));
 
+    $(".o_website_quote .bs-sidebar").affix({
+        offset: {
+            top: 0,
+            bottom: $('body').height() - $('#wrapwrap').outerHeight() + $("footer").outerHeight(),
+        },
+    });
 });
 
 odoo.define('website_quote.payment_method', function (require) {