feat: NoJs Admin View (#3059)

Adds a nojs blade template to be able to enable/disable extensions when one of them misbehaves.

framework/core/locale/core.yml

@@ -545,6 +545,20 @@ core:
 
   # Translations in this namespace are used in views other than Flarum's normal JS client.
   views:
+    # Translations in this namespace are displayed by the basic HTML admin index.
+    admin:
+      extensions:
+        caption: => core.ref.extensions
+        disable: Disable
+        empty: No installed extensions
+        enable: Enable
+        name: Extension Name
+        package_name: Package Name
+        version: Version
+      info:
+        caption: Application Info
+      title: Administration
+
     # Translations in this namespace are displayed by the Confirm Email interface.
     confirm_email:
       submit_button: => core.ref.confirm_email
@@ -673,6 +687,7 @@ core:
     edit: Edit
     edit_user: Edit User
     email: Email
+    extensions: Extensions
     icon: Icon
     icon_text: "Enter the name of any <a>FontAwesome</a> icon class, <em>including</em> the <code>fas fa-</code> prefix."
     load_more: Load More