Feat: backend supports with cookies

src/invidious/views/template.ecr

@@ -104,6 +104,17 @@
 					</div>
 				</div>
 
+				<% if CONFIG.backends %>
+				<div class="h-box">
+					<b>Switch Backend:</b>
+					<% CONFIG.backends.each do | backend | %>
+						<a href="/switchbackend?backend_id=<%= backend %>">
+							Backend<%= HTML.escape(backend) %>
+						</a> | 
+                    <% end %>
+				</div>
+				<% end %>
+
 				<% if CONFIG.banner %>
 					<div class="h-box">
 						<h3><%= CONFIG.banner %></h3>