feat: groups price calculator admin crud, booking/offer flow and api

templates/_partials/_flashes_admin.html.twig

@@ -0,0 +1,9 @@
+{% if app.session.flashBag.peek('error')|length > 0 %}
+    {% include '_partials/_toast.html.twig' with { level: 'warning', messages: app.flashes('error') } %}
+{% endif %}
+{% if app.session.flashBag.peek('success')|length > 0 %}
+    {% include '_partials/_toast.html.twig' with { level: 'success', messages: app.flashes('success') } %}
+{% endif %}
+{% if app.session.flashBag.peek('info')|length > 0 %}
+    {% include '_partials/_toast.html.twig' with { level: 'info', messages: app.flashes('info') } %}
+{% endif %}