[IMP] website: change CTA based on website main objective

If user selects 'schedule appointments' as main objective in the configurator
and if the website_calendar module is installed then the Call To Action of
snippets s_banner, s_cover and s_call_to_action is changed to 'Schedule an
appointment' and redirect user to '/calendar' on click.

task-2518565

closes odoo/design-themes#5

Related: odoo/odoo#71162
Related: odoo/enterprise#18690
Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>

theme_kea/views/snippets/s_cover.xml

@@ -14,7 +14,7 @@
                 </h1>
                 <p class="lead">Speed up your work with the last laptop. 3.4Ghz, 8 cores.<br/>
                 You’ll be unstoppable all day long (up to 11 hours).</p>
-                <p><a href="/contactus" class="btn btn-primary mb-2">Discover</a></p>
+                <p><a t-att-href="cta_btn_href" class="btn btn-primary mb-2"><t t-esc="cta_btn_text">Discover</t></a></p>
             </div>
         </xpath>
         <!-- Shape -->