UX: Introduce toggle-switch UI for plugins (#22910)

This commit makes some visual tweaks to the admin panel plugin list, and introduces functional 'toggle switches' for admins to enable/disable plugins more easily.

Co-authored-by: Jordan Vidrine <jordan@jordanvidrine.com>

plugins/styleguide/assets/javascripts/discourse/components/sections/atoms/02-buttons.hbs

@@ -162,4 +162,14 @@
       (fn (mut @dummy.toggleSwitchState) (not @dummy.toggleSwitchState))
     }}
   />
+  <DToggleSwitch
+    disabled="true"
+    @state={{true}}
+    title="Disabled with state=true"
+  />
+  <DToggleSwitch
+    disabled="true"
+    @state={{false}}
+    title="Disabled with state=false"
+  />
 </StyleguideExample>

plugins/styleguide/assets/stylesheets/styleguide.scss

@@ -195,6 +195,10 @@
     margin-right: 0.5em;
     margin-bottom: 0.5em;
   }
+
+  .d-toggle-switch {
+    display: inline-block;
+  }
 }
 
 .icons-examples,