WIP Add admin settings pages, reserved username config

Prototyping settings forms

app/views/admin/settings/services/index.html.erb

@@ -0,0 +1,39 @@
+<%= render HeaderComponent.new(title: "Settings") %>
+
+<%= render MainWithSidenavComponent.new(sidenav_partial: 'shared/admin_sidenav_settings') do %>
+  <section>
+    <h3>Lightning Network</h3>
+    <%= form_for(Setting.new, url: admin_settings_services_path) do |f| %>
+      <% if @errors && @errors.any? %>
+        <div>
+          <ul>
+            <% @errors.full_messages.each do |msg| %>
+              <li><%= msg %></li>
+            <% end %>
+          </ul>
+        </div>
+      <% end %>
+
+      <ul role="list" class="mt-2 divide-y divide-gray-200">
+        <li class="flex items-center justify-between py-6">
+          <div class="flex flex-col">
+            <label class="font-bold mb-1">Enable LNDHub integration</label>
+            <p class="text-gray-500 mb-0">LNDHub configuration present and wallet features enabled</p>
+          </div>
+          <%= f.check_box :lndhub_enabled, checked: Setting.lndhub_enabled?,
+                          disabled: true,
+                          class: "relative ml-4 inline-flex flex-shrink-0" %>
+        </li>
+        <li class="flex items-center justify-between py-6">
+          <div class="flex flex-col">
+            <label class="font-bold mb-1">Enable LNDHub admin panel</label>
+            <p class="text-gray-500 mb-0">LNDHub database configuration present and admin panel enabled</p>
+          </div>
+          <%= f.check_box :lndhub_admin_enabled, checked: Setting.lndhub_admin_enabled?,
+                          disabled: true,
+                          class: "relative ml-4 inline-flex flex-shrink-0" %>
+        </li>
+      </ul>
+    <% end %>
+  </section>
+<% end %>